Foam dressings for venous leg ulcers

  • Review
  • Intervention

Authors


Abstract

Background

Venous leg ulcers are a common and recurring type of chronic or complex wound that are associated with considerable cost to patients and to healthcare providers. Primary wound contact dressings are usually applied beneath compression devices with the aim of aiding healing. Foam dressings are used frequently, and a variety of foam products is available on the market. The evidence base to guide dressing choice, however, is sparse. 

Objectives

To determine the effects of foam dressings on the healing of venous leg ulcers.

Search methods

In October 2012 we searched The Cochrane Wounds Group Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); the Database of Abstracts of Reviews of Effects (DARE) (The Cochrane Library); the Economic Evaluation Database (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; EBSCO CINAHL. There were no restrictions based on language or date of publication.

Selection criteria

We included published or unpublished randomised controlled trials (RCTs) that evaluated the effects of any type of foam dressing in the treatment of venous ulcers.

Data collection and analysis

Two review authors independently performed study selection, data extraction and risk of bias assessment. Meta-analysis was undertaken when deemed feasible and appropriate.

Main results

Twelve RCTs (1023 participants) reporting 14 comparisons were included in this review. There was no difference in healing outcomes between hydrocellular foam dressings and polyurethane foam dressings (three RCTs). Pooled data across five RCTs (418 participants) showed no statistically significant difference between foam dressings and hydrocolloid dressings in the proportion of ulcers healed at 12 to 16 weeks (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.81 to 1.22). No statistically significant between-group differences in healing outcomes were detected when foam dressings were compared with: paraffin gauze (two RCTs); hydrocapillary dressing (one RCT); knitted viscose dressing (one RCT); and protease modulating matrix (one RCT). No statistically significant between-group differences in the proportion of participants experiencing adverse events were detected when hydrocellular foam dressings were compared with polyurethane foam dressings, or when foam dressings were compared with hydrocapillary, hydrocolloid, or knitted viscose dressings (one RCT for each comparison). Six RCTs were considered as being at overall high risk of bias, and the remaining six RCTs were considered to be at overall unclear risk of bias. No included RCT had an overall low risk of bias.

Authors' conclusions

The current evidence base does not suggest that foam dressings are more effective in the healing of venous leg ulcers than other wound dressing treatments. The evidence in this area is of low quality. Further evidence is required from well-designed and rigorously-conducted RCTs, that employ methods to minimise bias and report them clearly, before any definitive conclusions can be made regarding the efficacy of foam dressings in the management of venous leg ulcers.

Résumé scientifique

Pansements en mousse pour cicatrisation des ulcères veineux de jambe

Contexte

Les ulcères veineux de jambe sont un type courant et récurrent de plaies chroniques ou complexes qui sont associées à un coût considérable pour les patients et les prestataires de soins de santé. Les premiers pansements de contact avec la plaie sont généralement appliqués sous des dispositifs de compression dans le but de faciliter la cicatrisation. Les pansements en mousse sont fréquemment utilisés, et une grande diversité de produits en mousse est disponible sur le marché. La base des preuves guidant le choix du pansement est néanmoins peu fournie. 

Objectifs

Déterminer les effets des pansements en mousse sur la cicatrisation des ulcères veineux de jambe.

Stratégie de recherche documentaire

En octobre 2012, nous avons effectué des recherches dans le registre spécialisé du groupe Cochrane sur les plaies et contusions ; le registre Cochrane des essais contrôlés (CENTRAL) (The Cochrane Library) ; la base des résumés des revues systématiques hors Cochrane (DARE) (The Cochrane Library) ; l'Economic Evaluation Database (The Cochrane Library) ; Ovid MEDLINE ; Ovid MEDLINE (In-Process & Other Non-Indexed Citations) ; Ovid EMBASE ; EBSCO CINAHL. Il n’y avait aucune restriction basée sur la langue ou la date de publication.

Critères de sélection

Nous avons inclus les essais contrôlés randomisés (ECR) publiés ou non publiés ayant évalué les effets d'un type de pansement en mousse dans le traitement des ulcères veineux.

Recueil et analyse des données

Deux auteurs de la revue ont indépendamment sélectionné des études, extrait des données et évalué les risques de biais. Une méta-analyse a été réalisée quand elle était jugée faisable et appropriée.

Résultats principaux

Douze ECR, (1 023 participants) décrivant 14 comparaisons, ont été inclus dans cette revue. Il n'y avait aucune différence dans les résultats de cicatrisation entre les pansements en mousse hydrocellulaire et les pansements en mousse de polyuréthane (trois ECR). Les données regroupées à partir de cinq ECR (418 participants) n'ont révélé aucune différence statistiquement significative entre les pansements en mousse et les pansements hydrocolloïdes dans la proportion des ulcères guéris au bout de 12 à 16 semaines (risque relatif (RR) 1,00, intervalle de confiance (IC) à 95 % 0,81 à 1,22). Aucune différence statistiquement significative entre les groupes n'a été détectée dans les résultats de cicatrisation dans les comparaisons de pansements en mousse avec : la gaze imprégnée de paraffine (deux ECR) ; les pansements hydrocapillaires (un ECR) ; les pansements de viscose tricotée (un ECR) ; et la matrice modulatrice de la protéase (un ECR). Aucune différence statistiquement significative entre les groupes n'a été détectée dans la proportion des participants subissant des évènements indésirables dans les comparaisons de pansements en mousse hydrocellulaire avec les pansements en mousse de polyuréthane, ou dans les comparaisons de pansements en mousse avec les pansements hydrocapillaires, hydrocolloïdes, ou de viscose tricotée (un ECR pour chaque comparaison). Six ECR ont été considérés comme présentant un risque de biais globalement élevé, et les six autres ECR ont été considérés comme présentant un risque de biais globalement incertain. Aucun ECR inclus ne présentait un risque de biais globalement faible.

Conclusions des auteurs

La base des preuves actuelles ne suggère pas que les pansements en mousse sont plus efficaces pour la cicatrisation des ulcères veineux de jambe que d'autres traitements par pansements pour plaies. Les preuves dans ce domaine sont de faible qualité. Il est nécessaire d'obtenir d'autres preuves dans des ECR bien conçus et menés avec rigueur, qui emploient des méthodes pour minimiser les biais et les rapporter clairement, avant de pouvoir émettre des conclusions définitives concernant l'efficacité des pansements en mousse dans la prise en charge des ulcères veineux de jambe.

Plain language summary

Foam dressings for venous leg ulcers

Venous leg ulcers are a common and recurring type of chronic wound. Compression therapy (bandages or stockings) is used to treat venous leg ulcers. Dressings that aim to protect the wound and provide a moist environment to aid ulcer healing are applied beneath compression devices. Foam dressings are one of several types of dressing available. We evaluated the evidence from 12 randomised controlled trials that either compared different types of foam dressings, or compared foam dressings with other types of wound dressings. We found no evidence to suggest that polyurethane foam dressings are significantly better or worse than hydrocellular foam dressings in venous leg ulcer healing. Similarly, we found no evidence to suggest that foam dressings are significantly better or worse than other types of dressings (paraffin-impregnated gauze dressings, hydrocapillary dressings, hydrocolloid dressings, knitted viscose dressings, or protease-modulating matrix dressings), for the healing of venous leg ulcers. We found insufficient evidence to draw any conclusions regarding: adverse events, quality of life, costs, pain, or dressing performance. Overall, the current evidence is of low or unclear methodological quality. This limits the making of any specific recommendations regarding the use of foam dressings. Further, good quality evidence is required before definitive conclusions can be made regarding the role of foam dressings in the management of venous leg ulcers.

Résumé simplifié

Pansements en mousse pour cicatrisation des ulcères veineux de jambe

Les ulcères veineux de jambe sont un type courant et récurrent de plaies chroniques. La thérapie de compression (bandages ou bas de contention) est utilisée pour traiter les ulcères veineux de jambe. Des pansements qui visent à protéger la plaie et procurer un environnement humide pour faciliter la guérison des ulcères sont appliqués sous les dispositifs de compression. Les pansements en mousse ne sont que l'un des quelques types de pansements disponibles. Nous avons évalué les preuves issues de 12 essais contrôlés randomisés, soit ayant comparé différents types de pansements en mousse, soit ayant comparé des pansements en mousse à d'autres types de pansements pour plaies. Nous n'avons trouvé aucune preuve suggérant que les pansements en mousse de polyuréthane sont significativement plus efficaces ou plus mauvais que les pansements en mousse hydrocellulaire dans la cicatrisation des ulcères veineux de jambe. De même, nous n'avons trouvé aucune preuve suggérant que les pansements en mousse sont significativement plus efficaces ou plus mauvais que d'autres types de pansements (pansements de gaze imprégnée de paraffine, pansements hydrocapillaires, pansements hydrocolloïdes, pansements de viscose tricotée, ou pansements à matrice modulatrice de la protéase), pour la cicatrisation des ulcères veineux de jambe. Nous n'avons pas trouvé suffisamment de preuves pour tirer des conclusions concernant : les événements indésirables, la qualité de vie, les coûts, la douleur, ou les performances des pansements. Globalement, la qualité méthodologique des preuves actuelles est faible ou incertaine. Ceci limite la formulation de la moindre recommandation spécifique concernant l'utilisation des pansements en mousse. En outre, des preuves de bonne qualité sont nécessaires avant de pouvoir émettre des conclusions définitives concernant le rôle des pansements en mousse dans la prise en charge des ulcères veineux de jambe.

Notes de traduction

Traduit par: French Cochrane Centre 26th June, 2013
Traduction financée par: Pour la France : Minist�re de la Sant�. Pour le Canada : Instituts de recherche en sant� du Canada, minist�re de la Sant� du Qu�bec, Fonds de recherche de Qu�bec-Sant� et Institut national d'excellence en sant� et en services sociaux.

Summary of findings(Explanation)

Summary of findings for the main comparison. polyurethane foam dressing compared to hydrocellular foam dressing for venous leg ulceration
  1. 1 Note: lower risk of the outcome is less favourable (i.e. lower risk of healing) than higher risk. Estimates for baseline low and high risks of healing at 60 days (8 weeks) and 120 days (17 weeks) have been taken from a meta-analysis of RCTs evaluating different types of compression. The low risk estimate is based on a subset of participants with larger baseline ulcer area (greater than 5 cm squared). The high risk estimate is based on a subset of participants with smaller baseline ulcer surface area (5 cm squared or smaller). Most participants received a simple, low-adherent dressing plus four-layer bandage (O'Meara 2007).
    2 The hazard ratio estimate presented in the RCT paper was converted to a risk ratio using a formula described in the GRADE handbook (Schünemann 2009). The baseline risk of healing for the study population is based on the proportion of patients on hydrocellular foam dressing with healed ulcers at 24 weeks.
    3 RCT was at overall high risk of bias.
    4 Estimate based on single RCT; unable to assess heterogeneity.
    5 Number of patients recruited was lower than that estimated in the pre-specified sample size estimation.
    6 Estimate based on single RCT; unable to formally assess presence of publication bias.
    7 Estimate based on single, small RCT.
    8 The baseline risk of adverse events is derived from the study population (proportion of patients on hydrocellular foam dressing who reported any adverse event during the 24 week trial).

polyurethane foam dressing compared to hydrocellular foam dressing for venous leg ulceration
Patient or population: patients with venous leg ulceration
Settings: All settings.
Intervention: polyurethane foam dressing
Comparison: hydrocellular foam dressing
OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
Hydrocellular foam dressing Polyurethane foam dressing
Time to healing
Follow-up: 24 weeks
Study population1 RR 1.24
(0.91 to 1.49)2
156
(1 study)
⊕⊕⊝⊝
low 3,4,5,6
 
617 per 1000 765 per 1000
(562 to 920)
Low1
465 per 1000 577 per 1000
(423 to 693)
High1
757 per 1000 939 per 1000
(689 to 1000)
Proportion of participants with healed ulcers
Follow-up: 8 weeks
Study population1 RR 1.03
(0.6 to 1.78)
118
(1 study)
⊕⊕⊝⊝
low 3,4,6,7
 
300 per 1000 309 per 1000
(180 to 534)
Low1
198 per 1000 204 per 1000
(119 to 352)
High1
507 per 1000 522 per 1000
(304 to 902)
Proportion of participants with healed ulcers
Follow-up: 16 weeks
Study population1 RR 1.60
(0.75 to 3.42)
18
(1 study)
⊕⊕⊝⊝
low 3,4,6,7
 
500 per 1000 800 per 1000
(375 to 1000)
Low1
465 per 1000 744 per 1000
(349 to 1000)
High1
757 per 1000 1000 per 1000
(568 to 1000)
Proportion of participants with healed ulcers
Follow-up: 24 weeks
Study population1 RR 1.08
(0.85 to 1.37)
156
(1 study)
⊕⊕⊝⊝
low 3,4,5,6
 
617 per 1000 667 per 1000
(525 to 846)
Low1
465 per 1000 502 per 1000
(395 to 637)
High1
757 per 1000 818 per 1000
(643 to 1000)
Mean change in wound size, with adjustment for baseline sizeSee commentSee commentNot estimable0
(0)
See commentOutcome not reported (2 RCTs reported mean change in ulcer area, with no variance estimate, and no adjustment for baseline area).<BR/>
Proportion of participants experiencing adverse events
Follow-up: 24 weeks
272 per 1000 8 307 per 1000
(187 to 502)
RR 1.13
(0.69 to 1.85)
156
(1 study)
⊕⊕⊝⊝
low 3,4,5,6
 
Health-related quality of lifeSee commentSee commentNot estimable0
(0)
See commentOutcome not reported.
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Summary of findings 2 foam dressing compared to paraffin gauze dressing for venous leg ulceration

Summary of findings 2. foam dressing compared to paraffin gauze dressing for venous leg ulceration
  1. 1 Note: lower risk of the outcome is less favourable (i.e. lower risk of healing) than higher risk. Estimates for baseline low and high risks of healing at 120 days (17 weeks) have been taken from a meta-analysis of RCTs evaluating different types of compression. The low risk estimate is based on a subset of participants with larger baseline ulcer area (greater than 5 cm squared). The high risk estimate is based on a subset of participants with smaller baseline ulcer surface area (5 cm squared or smaller). Most participants received a simple, low-adherent dressing plus four-layer bandage (O'Meara 2007).
    2 RCT is at overall high risk of bias.
    3 Estimate based on single RCT; unable to assess heterogeneity.
    4 Estimate based on single, small RCT.
    5 Estimate based on single RCT; unable to formally assess presence of publication bias.

foam dressing compared to paraffin gauze dressing for venous leg ulceration
Patient or population: patients with venous leg ulceration
Settings: All settings.
Intervention: foam dressing
Comparison: paraffin gauze dressing
OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
Paraffin gauze dressing Foam dressing
Time to healingSee commentSee commentNot estimable0
(0)
See commentOutcome not reported.
Proportion of participants with healed ulcers
Follow-up: 17 weeks
Study population1 RR 1.34
(0.61 to 2.92)
71
(1 study)
⊕⊕⊝⊝
low 2,3,4,5
 
229 per 1000 306 per 1000
(139 to 667)
Low1
465 per 1000 623 per 1000
(284 to 1000)
High1
757 per 1000 1000 per 1000
(462 to 1000)
Mean change in wound size, with adjustment for baseline sizeSee commentSee commentNot estimable0
(0)
See commentOutcome not reported (2 RCTs reported change in mean or median ulcer area, with no adjustment for baseline area).<BR/>
Adverse eventsSee commentSee commentNot estimable0
(0)
See commentLimited data reported.
Health-related quality of lifeSee commentSee commentNot estimable0
(0)
See commentOutcome not reported.
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Summary of findings 3 foam dressing compared to hydrocapillary dressing for venous leg ulceration

Summary of findings 3. foam dressing compared to hydrocapillary dressing for venous leg ulceration
  1. 1 Note: lower risk of the outcome is less favourable (i.e. lower risk of healing) than higher risk. Estimates for baseline low and high risks of healing at 120 days (17 weeks) have been taken from a meta-analysis of RCTs evaluating different types of compression. The low risk estimate is based on a subset of participants with larger baseline ulcer area (greater than 5 cm squared). The high risk estimate is based on a subset of participants with smaller baseline ulcer surface area (5 cm squared or smaller). Most participants received a simple, low-adherent dressing plus four-layer bandage (O'Meara 2007).
    2 RCT at overall unclear risk of bias.
    3 Estimate based on single RCT; not possible to assess heterogeneity.
    4 Estimate based on single, small RCT.
    5 Estimate based on single RCT; not possible to formally assess publication bias.
    6 The baseline risk of adverse events is derived from the study population (proportion of patients on hydrocapillary dressings who experienced odour, maceration, leakage, erythema or eczema during the 12 month trial).

foam dressing compared to hydrocapillary dressing for venous leg ulceration
Patient or population: patients with venous leg ulceration
Settings: All settings.
Intervention: foam dressing
Comparison: hydrocapillary dressing
OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
Hydrocapillary dressing Foam dressing
Time to healingSee commentSee commentNot estimable0
(0)
See commentLimited information reported.
Proportion of participants with healed ulcers
Follow-up: 12 months
Study population1 RR 0.78
(0.5 to 1.21)
97
(1 study)
⊕⊕⊝⊝
low 2,3,4,5
 
510 per 1000 398 per 1000
(255 to 617)
Low1
465 per 1000 363 per 1000
(232 to 563)
High1
757 per 1000 590 per 1000
(378 to 916)
Mean change in wound size, with adjustment for baseline sizeSee commentSee commentNot estimable0
(0)
See commentOutcome not reported.
Proportion of participants experiencing adverse events
Follow-up: 12 months
163 per 1000 6 229 per 1000
(101 to 519)
RR 1.40
(0.62 to 3.18)
97
(1 study)
⊕⊕⊝⊝
low 2,3,4,5
 
Health-related quality of lifeSee commentSee commentNot estimable0
(0)
See commentLimited information provided.
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Summary of findings 4 foam dressing compared to hydrocolloid dressing for venous leg ulceration

Summary of findings 4. foam dressing compared to hydrocolloid dressing for venous leg ulceration
  1. 1 Note: lower risk of the outcome is less favourable (i.e. lower risk of healing) than higher risk. Estimates for baseline low and high risks of healing at 120 days (17 weeks) have been taken from a meta-analysis of RCTs evaluating different types of compression. The low risk estimate is based on a subset of participants with larger baseline ulcer area (greater than 5 cm squared). The high risk estimate is based on a subset of participants with smaller baseline ulcer surface area (5 cm squared or smaller). Most participants received a simple, low-adherent dressing plus four-layer bandage (O'Meara 2007).
    2 Four RCTs were at overall unclear risk of bias, and one was at overall high risk of bias.
    3 Insufficient number of RCTs available to undertake formal assessment of publication bias.
    4 The baseline risk of adverse events is derived from the study population (proportion of patients on hydrocolloid dressings who experienced any adverse event during the 12 week trial).
    5 RCT at overall unclear risk of bias.
    6 Estimate based on single RCT; unable to assess heterogeneity.
    7 Estimate based on single, small RCT.
    8 Estimate based on single RCT; unable to formally assess publication bias.

foam dressing compared to hydrocolloid dressing for venous leg ulceration
Patient or population: patients with venous leg ulceration
Settings: All settings.
Intervention: foam dressing
Comparison: hydrocolloid dressing
OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
Hydrocolloid dressing Foam dressing
Time to healingSee commentSee commentNot estimable0
(0)
See commentLimited data reported.
Proportion of participants with healed ulcers
Follow-up: 12-16 weeks
Study population1 RR 1.0
(0.81 to 1.22)
418
(5 studies)
⊕⊕⊕⊝
moderate 2,3
 
471 per 1000 471 per 1000
(382 to 575)
Low1
465 per 1000 465 per 1000
(377 to 567)
High1
757 per 1000 757 per 1000
(613 to 924)
Mean change in wound size, with adjustment for baseline sizeSee commentSee commentNot estimable0
(0)
See commentTwo RCTs reported change in wound area, but not with baseline adjustment.<BR/>
Proportion of participants experiencing adverse events
Follow-up: 12 weeks
236 per 1000 4 288 per 1000
(151 to 546)
RR 1.22
(0.64 to 2.31)
107
(1 study)
⊕⊕⊝⊝
low 5,6,7,8
 
Health-related quality of lifeSee commentSee commentNot estimable0
(0)
See commentOutcome not reported.
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Summary of findings 5 foam dressing compared to knitted viscose dressing for venous leg ulceration

Summary of findings 5. foam dressing compared to knitted viscose dressing for venous leg ulceration
  1. 1 Note: lower risk of the outcome is less favourable (i.e. lower risk of healing) than higher risk. Estimates for baseline low and high risks of healing at 90 days (12-13 weeks) have been taken from a meta-analysis of RCTs evaluating different types of compression. The low risk estimate is based on a subset of participants with larger baseline ulcer area (greater than 5 cm squared). The high risk estimate is based on a subset of participants with smaller baseline ulcer surface area (5 cm squared or smaller). Most participants received a simple, low-adherent dressing plus four-layer bandage (O'Meara 2007).
    2 RCT at overall high risk of bias.
    3 Estimate based on single RCT; not possible to assess heterogeneity.
    4 Estimate based on single, small RCT.
    5 Estimate based on single RCT; not possible to formally assess publication bias.

foam dressing compared to knitted viscose dressing for venous leg ulceration
Patient or population: patients with venous leg ulceration
Settings: All settings.
Intervention: foam dressing
Comparison: knitted viscose dressing
OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments
Assumed riskCorresponding risk
Knitted viscose dressing Foam dressing
Time to healingSee commentSee commentNot estimable0
(0)
See commentLimited information provided.
Proportion of participants with healed ulcers
Follow-up: 12 weeks
Study population1 RR 1.35
(0.89 to 2.05)
132
(1 study)
⊕⊕⊝⊝
low 2,3,4,5
 
348 per 1000 470 per 1000
(310 to 714)
Low1
311 per 1000 420 per 1000
(277 to 638)
High1
696 per 1000 940 per 1000
(619 to 1000)
Mean change in wound size, with adjustment for baseline sizeSee commentSee commentNot estimable0
(0)
See commentLimited information provided.
Proportion of participants experiencing adverse events
Follow-up: 12 weeks
   RR 5.00
(0.24 to 102.19)
132
(1 study)
⊕⊕⊝⊝
low 2,3,4,5
Assumed and corresponding risks not estimated because of zero event rate in knitted viscose group (3% in foam dressing group).
Health-related quality of lifeSee commentSee commentNot estimable0
(0)
See commentOutcome not reported.
*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio;
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Background

For definitions of terminology see Glossary of terms (Appendix 1).

Description of the condition

Venous leg ulcers are a common and recurring type of chronic, or complex, wound. They are usually caused by venous insufficiency (impaired venous blood flow) brought about by venous hypertension. Predisposing factors for venous hypertension include history of deep vein thrombosis (DVT), thrombophlebitis, leg trauma, arthritis, obesity, pregnancy and a sedentary lifestyle. These factors can result in damage to the valves in the leg veins allowing pathological (disease-causing) two-way blood flow instead of the normal one-way movement. A related issue is diminished calf muscle pump action. Both valvular and calf-muscle pump impairment can result in reduced venous blood flow leading to venous hypertension. This causes distension of the leg veins, oedema of the lower limb and leakage of circulatory fluids from the capillaries into the surrounding tissues. This, in turn, induces irritation and increased fragility of the epidermis (the outer layer of skin) leading to ulceration (Doughty 2007). The duration of venous leg ulceration ranges from a matter of weeks to more than 10 years and some people never heal (Moffatt 1995; Ruckley 1998; Vowden 2009a). Older patient age, longer wound duration and larger ulcer surface area have been reported as independent risk factors for delayed ulcer healing (Margolis 2004; Gohel 2005).

A review of 11 venous leg ulceration prevalence studies conducted in Australia and Europe estimated point prevalence as 0.1% to 0.3% (Nelzen 2008). Surveys undertaken in the UK estimated prevalence of venous leg ulceration as 0.023% in Wandsworth, London (Moffatt 2004); 0.044% in Hull and East Yorkshire (Srinivasaiah 2007); and 0.039% in Bradford and Airedale (Vowden 2009a; Vowden 2009b). The lower estimates reported in the UK surveys relative to the worldwide literature might be explained by differences in disease management or case definition, or both. We were unable to identify contemporary prevalence data for non-western countries. The epidemiological data have consistently suggested that prevalence increases with age, and is higher among women (Margolis 2002; Graham 2003; Lorimer 2003; Moffatt 2004; Vowden 2009a).

Diagnosis of venous leg ulceration can be made according to the appearance and location of the ulcer. Clinical practice guidelines recommend the use of clinical history, physical examination, laboratory tests and haemodynamic assessment (RCN 2006; SIGN 2011a). The latter typically includes an assessment of arterial supply to the leg using the ankle-brachial pressure index (ABPI), measured using a hand-held Doppler ultrasound device. An ABPI measurement of more than 0.8 is generally used to rule out the co-existence of clinically significant peripheral arterial disease in a leg ulcer that has been diagnosed as due to venous insufficiency (Moffatt 2007).

Leg ulcers are associated with considerable cost to patients and to healthcare providers. Two systematic reviews summarised the literature on health-related quality of life in patients with leg ulcers (Persoon 2004; Herber 2007). Both included qualitative and quantitative evaluations and reported that the presence of leg ulceration was associated with pain, restriction of work and leisure activities, impaired mobility, sleep disturbance, reduced psychological well-being and social isolation.

The cost of treating an unhealed leg ulcer in the UK has been estimated to be around GBP 1300 per year at 2001 prices (Iglesias 2004). Another evaluation estimated the average cost of treating a venous leg ulcer in the UK (based on costs for material for dressing changes) as lying between EUR 814 and EUR 1994, and, in Sweden, as lying between EUR 1332 and EUR 2585 (price year 2002), with higher costs associated with larger and more chronic wounds (Ragnarson Tennvall 2005). This reflected findings from a more recent evaluation conducted in Hamburg, Germany, recruiting 502 community based adult patients with any type of leg ulcer. The total mean annual cost of illness for leg ulcers was estimated as EUR 9060 per patient (price year 2006), taking account of direct, indirect and intangible costs from a societal perspective. Direct costs included all expenses directly related to leg ulcer care (dressings, bandages, topical agents, systemic treatment, diagnostic procedures, clinician fees, in-patient treatment costs and transport); indirect costs related to loss of productivity; and intangible costs included impact on health-related quality of life. Estimates ranged from zero cost (i.e. no treatment) to EUR 44,462, with higher costs associated with arterial aetiology of the ulcer, larger wound size and no history of wound closure (Augustin 2012). In Bradford, in the UK, GBP 1.69 million was spent on dressings and compression bandages, and GBP 3.08 million on nursing time (estimates derived from resource use data for all wound types, not just venous leg ulcers) during the financial year 2006-2007 (Vowden 2009c). We were not able to identify further contemporary international cost data.

Compression therapy (bandages or stockings) is now considered to be the cornerstone of venous leg ulcer management (Moffatt 2007; O'Meara 2009). Primary wound contact dressings (i.e. dressings in direct contact with the wound bed) are usually applied underneath compression devices. A range of other interventions may be used concurrently with compression, including debriding agents (Davies 2005), vasoactive drugs (Robson 2006), fibrinolytic therapy (Robson 2006), physical therapies (Flemming 2001; Ravaghi 2006; Al-Kurdi 2008), and topical applications (Robson 2006).

Description of the intervention

Primary wound contact dressings are applied with the aim of aiding healing, providing comfort, controlling exudate (the fluid produced by wounds) and helping to prevent bandages and stockings from adhering to the wound bed. The ideal conditions required for wound healing in terms of dressing application have been explained as follows: maintenance of a moist wound environment without risk of maceration (excessive softening of skin because of being constantly wet); avoidance of toxic chemicals, particles or fibres in the dressing fabric; a minimal number of dressing changes; and maintenance of an optimum pH level (balanced acidity and alkalinity) (BNF 2013).

Several types of wound dressing are available and costs vary (Appendix 2). For example, there can be a six-fold difference in the UK unit price of a 9.5 cm x 9.5 cm non-adherent (knitted viscose) dressing compared with a 10 cm x 10 cm polyurethane foam dressing (BNF 2013).

Foam dressings were one of the first advanced (modern) dressings to be used in wound management and are available internationally. In the UK, foam dressings are one of a variety of advanced wound dressings that are currently available, and are used frequently, being common to many wound-care formularies. One of the purported advantages of foam dressings is their exudate handling properties, not only through absorption of exudate into the fabric of the dressing, but also via transmission through a top sheet, keeping moisture away from the wound margin (and thereby potentially reducing the risk of maceration of peri-ulcer skin). If necessary, foam dressings can be used in combination with a secondary dressing, with the latter absorbing excess exudate. It has been suggested that foam dressings can remain in place for longer than other dressing types, which provides potential to decrease the frequency of dressing changes and, therefore, reduce costs. Another suggested benefit is non-traumatic dressing removal (Sussman 2010). There is a variety of foam products on the market, and these vary in their ability to absorb exudate. Some are suitable for only lightly- to moderately-exuding wounds, whilst others have a greater fluid-handling capacity.

Several potential disadvantages of foam dressings have been noted, namely, the possibility of saturation leading to maceration of healthy peri-ulcer skin and also potential reduction in fluid-handling capacity if used beneath compression devices.

Examples of foam dressings currently available in the UK include Allevyn® Non-Adhesive (Smith and Nephew) and Biatain® Non-Adhesive (Coloplast). Appendix 2 provides a description of all wound dressings categorised by the British National Formulary (BNF 2013).

How the intervention might work

Findings from research based on animal models suggest that acute wounds heal more quickly when the wound surface is kept moist, so that formation of a hard scab or eschar is prevented (Winter 1963). A moist environment is also thought to provide optimal conditions for promoting autolytic debridement (the breakdown of dead cells lying on top of the wound bed), which is sometimes considered to be an important part of the healing pathway (König 2005). It is purported that foam dressings manage exudate, provide a moist wound healing environment and promote healing (BNF 2013).

Why it is important to do this review

Wound dressings are a key part of the treatment pathway when caring for venous leg ulcers. Most will be used in combination with compression systems, and guidelines are necessary to help make decisions regarding the value, and best use, of the available dressings. Several types of wound dressing are available and costs vary considerably, however, the evidence base to guide dressing choice is sparse. A previous Cochrane review that evaluated different wound dressings for venous leg ulcers concluded that the type of dressing applied beneath compression had not been shown to affect ulcer healing (Palfreyman 2006). The review authors concluded that there was no evidence of benefit for foam dressings compared with non-adherent dressings, nor for different types of foam dressings compared with one another.  

This review will now update part of the previous Palfreyman 2006 Cochrane review and will be one of several Cochrane reviews investigating the use of dressings in the treatment of venous leg ulcers. Each review will focus on a particular dressing type, which, in this review, will be foam dressings. These reviews will eventually be summarised in an overview of reviews (Becker 2011), which will draw together all existing Cochrane review evidence regarding the use of dressings in the treatment of venous leg ulcers.

Objectives

To determine the effects of foam dressings compared with alternative dressings, non-dressing treatments or no dressing, with or without concurrent compression therapy, on the healing of venous leg ulcers; and to determine the comparative effects of foam dressings with alternatives on health-related quality of life, costs, pain, dressing performance (management of wound exudate and ease of removal) and adverse effects.

Methods

Criteria for considering studies for this review

Types of studies

We included randomised controlled trials (RCTs), either published or unpublished, that evaluated the effects of any type of foam dressing in the treatment of venous leg ulcers, irrespective of publication status or language. RCTs reported in abstract form only were eligible for inclusion, provided adequate information was presented in the abstract, or was available from the authors. Studies using quasi-randomisation were excluded.

Types of participants

RCTs recruiting people described in the primary report as having venous leg ulcers, managed in any setting, were eligible for inclusion. As the method of diagnosis of venous ulceration may vary, we accepted definitions as used in the RCTs. We included RCTs that recruited samples comprising people with venous leg ulcers and people with other types of wounds (e.g. arterial ulcers, diabetic foot ulcers) if the results for people with venous ulcers were presented separately (or separate data available from the authors), or if the majority of participants (75% or more in each arm) had leg ulcers of venous aetiology (origin).

Types of interventions

The primary intervention of interest was foam wound dressings. For ease of comparison we categorised dressings according to the British National Formulary (BNF 2013). We have presented generic names where possible, also providing trade names and manufacturers where available. It is important, however, to note that manufacturers and distributors of dressings may vary from country to country, and dressing names may also differ. We did not include RCTs evaluating foam dressings impregnated with antimicrobial, antiseptic or analgesic agents, as these interventions are evaluated in other Cochrane reviews (Briggs 2012; O'Meara 2010), and will be captured in the proposed overview of reviews (see Why it is important to do this review). RCTs evaluating wound dressing pads, hydrocolloid dressings, hydrogels and alginate dressings will be covered in other, separate Cochrane reviews and are included in this review only if they are comparators to foam dressings. Forthcoming, related Cochrane reviews on dressings for venous leg ulcers will, along with this review, update the review by Palfreyman 2006.

We included any RCT in which the presence or absence of a specific foam dressing was the only systematic difference between treatment groups; and in which a foam dressing was compared with other wound dressings (including alternative foam dressings), non-dressing treatments (for example, topical applications) or no dressing. We included RCTs of foam dressings, irrespective of whether compression therapy was reported as a concurrent treatment.

Types of outcome measures

Primary outcomes

The primary outcome for the review was complete wound healing.

Wound healing is measured and reported by trialists in many different ways, including time to complete wound healing, the proportion of wounds healed during follow up and rates of change of wound size. For this review we regarded RCTs that reported one or more of the following as providing the best measures of outcome in terms of relevance and rigour:

  • time to complete wound healing (correctly analysed using survival, time-to-event approaches, ideally with adjustment for relevant covariates such as baseline size);

  • the proportion of ulcers healed during follow up (frequency of complete healing);

  • and change (and rate of change) in wound size, with adjustment for baseline size.

We considered evidence from RCTs that reported mean or median time to healing without survival analysis (i.e. they regarded time to healing as a continuous measure without censoring), and those that measured and reported change or rate of change in wound size without adjustment for baseline size, as less rigorous assessments of these outcomes, and did not use data reported in this manner to populate the Summary of Findings tables (see Summary of Findings tables).

Secondary outcomes

The secondary outcomes for the review were:

  • rates of all reported adverse events (e.g. infection, eczema, maceration);

  • health-related quality of life (measured using a validated standardised generic questionnaire such as EQ-5D, SF-36, SF-12 or SF-6, or validated disease-specific questionnaire) preferably with follow-up estimates adjusted for baseline scores;

  • cost (including cost or cost-effectiveness estimations, as well as measurements of resource use such as number of dressing changes, dressing wear time and nurse time);

  • pain (e.g. at dressing change, between dressing changes or over the course of treatment);

  • dressing performance (exudate management and ease of removal or adherence to the wound bed).

Search methods for identification of studies

Electronic searches

In October 2012 we searched the following electronic databases for potentially relevant RCTs:

  • the Cochrane Wounds Group Specialised Register (searched 25 October 2012);

  • the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 10);

  • the Database of Abstracts of Reviews of Effects (DARE) (The Cochrane Library 2012, Issue 10);

  • the Economic Evaluation Database (The Cochrane Library 2012, Issue 10);

  • Ovid MEDLINE (1948 to October Week 3 2012);

  • Ovid MEDLINE (In-Process & Other Non-Indexed Citations, 25 October 2012);

  • Ovid EMBASE (1974 to 2012 Week 42);

  • EBSCO CINAHL (1982 to 19 October 2012).

We used the following search strategy in the Cochrane Central Register of Controlled Trials (CENTRAL):

#1 MeSH descriptor: [Occlusive Dressings] explode all trees 436
#2 foam*:ti,kw,ab 929
#3 (ActivHeal or Allevyn or Avazorb or Biatain or Copa or LyoFoam or PermaFoam or PolyMem or Suprasorb or Tegaderm or Tielle or Transobent or Trufoam or UrgoCell):ti,kw,ab 171
#4 #1 or #2 or #3 1465
#5 MeSH descriptor: [Leg Ulcer] explode all trees1064
#6 ((varicose next ulcer*) or (venous next ulcer*) or (leg next ulcer*) or (stasis next ulcer*) or (crural next ulcer*) or "ulcus cruris" or "ulcer cruris"):ti,ab,kw 1408
#7 #5 or #6 1830
#8 #4 and #7 126

The search strategies for Ovid MEDLINE, Ovid EMBASE and EBSCO CINAHL can be found in Appendix 3. We combined the Ovid MEDLINE search with the Cochrane Highly Sensitive Search Strategy for identifying randomised trials in MEDLINE: sensitivity- and precision-maximising version (2008 revision) (Lefebvre 2011). We combined the EMBASE search with the Ovid EMBASE filter developed by the UK Cochrane Centre (Lefebvre 2011). We combined the CINAHL searches with the RCT filters developed by the Scottish Intercollegiate Guidelines Network (SIGN 2011b). We did not restrict searches with respect to language or date of publication.

We searched for ongoing RCTs in the World Health Organization International Trial Registry Platform (http://www.who.int/ictrp/en/ accessed 1 August 2012) and the ISRCTN (International Standard Randomised Controlled Trial Number) register (http://www.controlled-trials.com/isrctn/ accessed 1 August 2012) using the search term 'leg ulcer'.

Searching other resources

We attempted to contact trialists to obtain unpublished data and information as required, along with manufacturers to request information about ongoing or as yet unpublished RCTs (for a list of manufacturers see Appendix 4). We also searched the reference lists of RCT reports identified for inclusion and of other systematic review articles. 

Data collection and analysis

Selection of studies

Two review authors independently assessed the titles and abstracts retrieved by the searches for relevance. After this initial assessment, we obtained full text copies of all RCT reports felt to be potentially relevant. Two review authors then independently checked the full papers for eligibility, with disagreements resolved by discussion, and, where required, referral to the editorial base of the Cochrane Wounds Group. We recorded all reasons for exclusion.

We have presented our study selection process as a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram (Liberati 2009) (see Results of the search).

Data extraction and management

We extracted and summarised details of the eligible RCTs using a data extraction sheet. We extracted the data from RCT reports using an Excel spreadsheet designed to capture the information detailed below. Initially, we piloted the spreadsheet with a sample of eligible RCTs, to explore any issues that might arise in relation to the data extraction process. We expanded and amended the spreadsheet as necessary after the piloting process. Two review authors performed independent data extraction of all included RCTs, after which both data extractions were compared, and a final version agreed. We resolved any disagreements by discussion. If data were missing from reports we attempted to contact the trial authors to obtain the missing information. We included RCTs published as duplicate reports (parallel publications) once, using all associated reports to extract a maximal amount of information, but ensuring that data were not duplicated in the review. We extracted the following information:

  • trial authors;

  • year of publication;

  • country where RCT performed;

  • setting of care;

  • unit of investigation – participant, leg or ulcer;

  • overall sample size and methods used to estimate statistical power (relates to the target number of participants to be recruited, the clinical difference to be detected and the ability of the RCT to detect this difference);

  • participant selection criteria;

  • number of participants randomised to each treatment arm;

  • baseline characteristics of participants per treatment arm (gender, age, baseline ulcer area, ulcer duration, prevalence of co-morbidities such as diabetes, prevalence of clinically infected wounds or colonised wounds, previous history of ulceration, baseline levels of wound exudate, and participant mobility);

  • details of the dressing/treatment regimen prescribed for each arm including details of concomitant therapy, for example, compression;

  • duration of treatment;

  • duration of follow up;

  • statistical methods used for data analysis;

  • primary and secondary outcomes measured;

  • primary and secondary outcome data by treatment arm;

  • adverse effects of treatment (per treatment arm with numbers and type);

  • withdrawals (per treatment arm with numbers and reasons); and

  • source of trial funding.

Assessment of risk of bias in included studies

Two review authors independently assessed each included RCT report using the Cochrane Collaboration tool for assessing risk of bias (Higgins 2011a). This tool addresses specific domains, namely: sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data and selective outcome reporting (see Appendix 5 for details of the criteria on which judgements were based). For blinded outcome assessment we made separate judgements for primary and secondary outcomes. As the primary outcomes for this review (wound healing), whichever way measured, are subject to potential observer or measurement bias, blinding of outcome assessment is important. Similarly we made separate judgements for primary and secondary outcomes for the domain of incomplete outcome data. In order to assess selective outcome reporting, we sought protocols for all included RCTs. Where protocols were unavailable, we made a judgement based on congruence of information in methods and results sections of reports of RCTs. We classified RCTs as being at overall high risk of bias if they were rated as 'high' for any one of three key domains (allocation concealment, blinding of outcome assessors and completeness of outcome data). We classified RCTs as being at overall unclear risk of bias if any one of the three key domains was rated as unclear. RCTs were judged to be at overall low risk of bias only if all three key domains were rated as low risk.

We have presented our assessment of risk of bias findings using 'Risk of bias' summary figures. Figure 1 is a summary of information across all included RCTs and Figure 2 shows a cross-tabulation of each individual RCT with each risk of bias item. This display of internal validity indicates the weight the reader may give the results of each RCT.

Figure 1.

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included trials.

Figure 2.

Risk of bias summary: review authors' judgements about each risk of bias item for each included trial.

Measures of treatment effect

We have presented a narrative overview of all included RCTs, with results grouped according to the comparator intervention. We undertook statistical pooling of outcome data on groups of RCTs considered to be sufficiently similar in terms of design and characteristics of participants, interventions and outcomes, using Cochrane RevMan software (version 5.2) (RevMan 2012). We reported estimates for dichotomous outcomes (e.g. number of ulcers healed) as risk ratios (RRs) with associated 95% confidence intervals (CI). We reported estimates for continuous data outcomes (e.g. absolute or relative change in ulcer area and healing rate) as a mean difference (MD) with 95% CI. We planned to report estimates of time to healing and plot hazard ratios where available from the included RCTs. Where hazard ratios were not reported we planned, where possible, to extrapolate these using other reported data relating to time to healing (Parmar 1998). Where RCTs reported adverse events in sufficient detail (e.g. the number of participants who experienced at least one adverse event) we analysed these as dichotomous data. Where it was unclear whether the denominator was the total number of adverse events, or the number of participants, we reported these data narratively. Where adverse events were reported as dressing-related we analysed the data separately.

Unit of analysis issues

We recorded whether RCT reports specified participants, limbs or ulcers as the units of allocation and analysis. In cases where multiple limbs or ulcers on the same individual were studied, we planned to note whether the trialists' analysis was appropriate (i.e. correctly taking account of highly correlated data) or inappropriate (i.e. considering outcomes for multiple ulcers on the same participant as independent). Where the number of wounds appeared to equal the number of participants, we assumed that the participant was the unit of analysis, unless otherwise stated.

Dealing with missing data

Missing data are a common problem in RCTs. Excluding randomised participants from the analysis or ignoring those participants lost to follow up can compromise the process of randomisation and introduce bias. Where RCTs reported dichotomous complete healing outcomes for only those participants who completed the RCT (i.e. participants withdrawing and lost to follow up were excluded from the analysis), we treated the participants who were not included in the analysis as if their wound did not heal (that is, they were included in the denominator but not the numerator for healing outcomes). Where results were reported for participants who completed the RCT without specifying the numbers that were randomised per group initially, we presented only complete case data. For other outcomes we presented data for all participants randomised, where reported; otherwise we based estimates on complete cases only.

Assessment of heterogeneity

We considered clinical heterogeneity (that is the degree to which RCTs appear similar in terms of participants, intervention type and duration and outcome type) and statistical heterogeneity. We assessed statistical heterogeneity using the Chi² test (P value less than 0.10 was considered to indicate statistically significant heterogeneity) in conjunction with the I² statistic (Higgins 2003). The I² statistic examines the percentage of total variation across RCTs due to heterogeneity rather than chance (Higgins 2003). We considered that I² values of 40% or less indicated a low level of heterogeneity and values of 75% or more represented very high heterogeneity (Deeks 2011).

Assessment of reporting biases

Reporting biases arise when the dissemination of research findings is influenced by the nature and direction of results. Publication bias is one of a number of possible causes of 'small study effects' – a tendency for estimates of the intervention effect to be more beneficial in smaller trials. Funnel plots allow a visual assessment of whether small study effects may be present in a meta-analysis. A funnel plot is a simple scatter plot of the intervention effect estimates from individual RCTs against some measure of each trial’s size or precision (Sterne 2011). We planned to present funnel plots for meta-analyses comprising 10 RCTs or more using RevMan 5.2.

Data synthesis

We have presented a narrative overview of the included RCTs. Where appropriate, we have presented meta-analyses of outcome data using RevMan 5.2. The decision to pool data in a meta-analysis depended upon the availability of outcome data and the assessment of between-trial heterogeneity. For comparisons where there was no apparent clinical heterogeneity and the I² value was 40% or less, we applied a fixed-effect model. Where there was no apparent clinical heterogeneity and the I² value was greater than 40%, we planned to apply a random-effects model. However, we planned not to pool data where heterogeneity was very high (I² values of 75% or above).

For the dichotomous outcomes we have presented the summary estimate as a RR with 95% confidence intervals (CI). For outcomes reported as count data (i.e. where the denominator was not the number of participants), a between-group difference with 95% CI was not estimated. Where continuous outcomes were measured in the same way across RCTs, we have presented a mean difference (MD) with 95% CI. Where variance data were not available, a mean between-group difference with 95% CI was not estimated. We planned to present a standardised mean difference (SMD) when RCTs measured the same outcome using different methods. For time-to-event data, we planned to plot (and if appropriate pool) estimates of hazard ratios and 95% CIs as they were presented in the RCT reports using the generic inverse variance method in RevMan 5.2. Where hazard ratios were not reported, and could not be extrapolated, a between-group difference with 95% CI was not estimated.

Summary of Findings tables

We have presented the main results of the review in Summary of Findings tables. These tables present key information concerning the quality of the evidence, the magnitude of the effects of the interventions examined, and the sum of the available data for the main outcomes (Schünemann 2011a). The Summary of Findings tables also include an overall grading of the evidence related to each of the main outcomes using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. The GRADE approach defines the quality of a body of evidence with regard to the extent to which one can be confident that an estimate of effect or association is close to the true quantity of specific interest. Quality of a body of evidence involves consideration of within-trial risk of bias (methodological quality), directness of evidence, heterogeneity, precision of effect estimates and risk of publication bias (Schünemann 2011b). We planned to present the following outcomes in the Summary of Findings tables:

  • time to complete ulcer healing where analysed using appropriate survival analysis methods;

  • proportion of ulcers completely healing during the trial period;

  • change in wound size, when adjusted for baseline size;

  • adverse events; and

  • health-related quality of life.

Subgroup analysis and investigation of heterogeneity

We planned to conduct subgroup analyses according to whether RCTs assessed the dressing of interest with or without the application of compression therapy. We planned to exclude RCTs in which the presence or absence of compression therapy was not clearly indicated from this subgroup analysis.

Sensitivity analysis

Where data permitted, we planned to undertake sensitivity analyses according to risk of bias, excluding RCTs that were judged as being at overall high or unclear risk of bias (i.e. rated as high or unclear respectively for any one of three key domains - allocation concealment, blinding of outcome assessors and completeness of outcome data). We also planned to undertake a sensitivity analysis in which we excluded RCTs that reported complete healing outcomes for only those participants who completed the RCT, and RCTs that reported results for participants who completed the RCT without specifying the numbers that were randomised per treatment group initially.

Results

Description of studies

See Characteristics of included studies; Characteristics of excluded studies; Characteristics of studies awaiting classification; Characteristics of ongoing studies.

Results of the search

The search strategy identified 436 records in total. Of these, 256 were retrieved from electronic bibliographic databases, 174 were found from registers of ongoing trials, four were identified from examination of reference lists, and two were obtained as unpublished reports whilst requesting trial protocols for the risk of bias assessment. No references were obtained as a result of contact with wound dressing manufacturers (Appendix 4).  Eight manufacturers out of 14 contacted confirmed that there were no ongoing or recently completed RCTs of foam dressings; no replies were received from the remainder. Three hundred and fifty-five records were excluded because of irrelevance on the basis of information in titles and abstracts or details of ongoing trials.

Eighty-one full text reports were retrieved, comprising: 76 published reports; three records of ongoing trials; and two unpublished reports. Following assessment of full text reports against the review's study selection criteria, 43 full text articles were excluded that reported 30 unique studies. Reasons for exclusion were as follows:

See Characteristics of excluded studies for further details.

Twelve RCTs (reported in 32 articles) were included in the review (see next section for further details). In addition, two RCTs (reported in three articles) were classified as awaiting assessment (Jørgensen 2008; Romanelli 2008), and three RCTs (reported in three articles) were ongoing (Vas 2008; Bayer 2009; Badiavas 2011). See Characteristics of studies awaiting classification and Characteristics of ongoing studies for further details. The study selection process is shown in Figure 3.

Figure 3.

Flow diagram of the study selection process

Included studies

We included 12 RCTs that recruited 1023 participants (see Characteristics of included studies). One trial took place entirely in North America (Weiss 1996); another jointly in North America and Europe (Vanscheidt 2004); while the remaining RCTs took place in EU countries. Six were multicentred RCTs (Callam 1992; Thomas 1997; Andersen 2002; Vanscheidt 2004; Norkus 2005; Franks 2007). The remainder were conducted at single centres. Two RCTs were of a factorial design that allowed an evaluation of two dressings and two compression bandage systems (Callam 1992; Franks 2007); and another two were described as pilot studies (Weiss 1996; Andriessen 2009). The included RCTs were reported from 1990 to 2009.

Sample sizes ranged from 12 to 159 participants. Two RCTs reported that a sample size calculation had been performed (Vanscheidt 2004; Franks 2007).

The mean age of participants ranged from 55 to 78 years. The proportion of female participants ranged from 33% to 89%. Where reported, the majority of RCTs recruited participants who were ambulatory.

With the exception of two RCTs that recruited participants with leg ulcers of various aetiologies (Andersen 2002; Norkus 2005), all participants had leg ulcers of venous aetiology. An APBI less than 0.80 was an exclusion criterion in the majority of RCTs, confirmed, where reported, using hand-held Doppler or digital photoplethysmography.

The dressing comparisons evaluated by the included RCTs were as follows:

All RCTs reported the use of compression therapy for eligible participants, with one exception, where no details were provided (Banerjee 1990). The length of treatment ranged from four weeks to twelve months. Treatment settings were mainly leg ulcer clinics, hospital outpatients clinics and the community. 

With one exception (Andriessen 2009), all RCTs reported the proportion of ulcers completely healed at the end of treatment. Time to complete ulcer healing was assessed by eight RCTs (Callam 1992; Bowszyc 1995; Weiss 1996; Andersen 2002; Charles 2002; Vanscheidt 2004; Norkus 2005; Franks 2007), and change in ulcer size or healing rate was assessed by eight RCTs (Banerjee 1990; Callam 1992; Weiss 1996; Thomas 1997; Andersen 2002; Charles 2002; Vanscheidt 2004; Andriessen 2009).

Risk of bias in included studies

A summary of the risk of bias assessment is presented in Figure 1 and Figure 2.

Allocation

Generation of the randomisation sequence

One RCT reported using a computer-generated programme (Andriessen 2009), and another used minimisation (Charles 2002). These two RCTs were considered to be at low risk of bias for generation of the randomisation sequence. A judgement of low risk of bias for this domain was also made for Franks 2007 following personal communication with the trial authors in connection with a separate review. The remaining nine RCTs did not describe the method used for random sequence generation clearly and were classified as being at unclear risk of bias for this domain.

Concealment of the allocation process

One RCT reported using sequentially-numbered, sealed, opaque envelopes (Andersen 2002), and was considered to be at low risk of bias. A judgement of low risk of bias for this domain was also made for Franks 2007 following personal communication with the RCT authors. Two RCTs reported the use of envelopes for treatment group allocation, but did not specify whether the envelopes were opaque and sequentially-numbered and, therefore, were classified as being at unclear risk of bias (Andriessen 2009; Thomas 1997). The remaining eight RCTs did not clearly describe the method of treatment group allocation and were also classified as being at unclear risk of bias for this domain.

Blinding

Blinding of participants and personnel

Two RCTs provided detail in the report that the RCT was not blinded (Weiss 1996; Andersen 2002), and one trialist provided detail via personal communication that the RCT was not blinded (Franks 2007). These RCTs were judged to be at a high risk of bias for blinding of participants and personnel. One report stated that the RCT was ‘open’ but did not provide further details regarding whether or not the participants or personnel were blinded, and was classified as having an unclear risk of bias for this domain (Thomas 1997). The remainder of the included RCT reports (eight RCTs) did not provide statements regarding blinding of participants or personnel, and were also judged to be at unclear risk of bias.

Blinding of outcome assessment

One RCT reported that the assessors were blinded to the treatment, and was judged to be at low risk of bias for blinded outcome assessment (Andriessen 2009). Two RCTs reported that the RCT was not blinded, and were judged to be at a high risk of bias for this domain (Weiss 1996; Andersen 2002), as was another following personal communication with the trial authors (Franks 2007). One RCT was described as ‘open’ but did not state whether the outcome assessment was blinded, and was classified as unclear risk of bias (Thomas 1997). The remainder of the included RCT reports (seven RCTs) did not provide details about blinded outcome assessment, and were also judged to be at unclear risk of bias for this domain.

Incomplete outcome data

One RCT reported that all randomised participants completed the RCT (Andriessen 2009), and another reported that although dropouts had occurred (reasons reported and numbers balanced across groups), analyses had been according to intention-to-treat (ITT) (Franks 2007). One RCT reported that some participants withdrew from both treatment groups, but all participants randomised were accounted for in the tabulated results (Bowszyc 1995). One RCT report did not include a statement regarding participant withdrawal, however, it appeared that all participants were included in the final analysis (Zuccarelli 1992). These RCTs were all considered to be at a low risk of attrition bias. 

Andersen 2002 reported an imbalance of participants withdrawing across groups, and that the participants who withdrew were not included in the final analysis. Banerjee 1990 did not explain why some participants, other than those reported as withdrawing, were not included at follow up. Callam 1992 reported reasons for withdrawal, that withdrawals were balanced across groups, and that the analysis was undertaken as ITT, however, the report suggested that the missing participant data was not included in the final analysis. Although all participants were included in the healing analyses (ITT) of Charles 2002, not all recruited participants were included in the analyses of secondary outcomes. These four RCTs were all judged to be at a high risk of bias for this domain.

One RCT reported the use of ITT, but did not define the ITT population and presented some outcomes that did not include all of the randomised participants (Norkus 2005). The RCT by Thomas 1997 did not provide any statement regarding participant withdrawal, and, whilst all patients randomised were accounted for in tabulated healing outcomes, not all participants were accounted for in the text that reported proportions of participants whose ulcers reduced in size. The RCT by Vanscheidt 2004 reported that 29% of all participants withdrew before 9.6 weeks, but did not report the numbers withdrawing according to their group, or state whether any participants had withdrawn after 9.6 weeks. The RCT report by Weiss 1996 suggested that all participants were included in the final analysis of healing, but it was not clear whether pain and other outcomes included all participants randomised. These four RCTs were all judged to be at an unclear risk of bias for this domain.

Selective reporting

Six RCTs were considered to be at low risk of bias for this domain as, although the RCT protocols were not available, all RCT outcomes described in the methods section of the report were included in the results section (Banerjee 1990; Zuccarelli 1992; Weiss 1996; Thomas 1997; Norkus 2005; Andriessen 2009). 

Two RCTs were considered to be at high risk of bias for this domain as the RCT reports included results for outcomes that were not described as being evaluated in the methods section of the report (number of weekly dressing changes, Bowszyc 1995; and adverse events, Charles 2002).

RCT protocols were provided for four of the included RCTs (Callam 1992; Andersen 2002; Vanscheidt 2004; Franks 2007). The RCT by Callam 1992 was considered to be at low risk of bias for this domain as all outcomes mentioned in the RCT protocol were presented in the RCT report. The RCT by Andersen 2002 was considered to be at unclear risk of bias as, although all RCT outcomes described in the published report were in the supplied RCT protocol, it was unclear from the published report what the primary outcome was (maceration in the protocol). A secondary outcome of ‘ability to adapt’ in the protocol (translated from Danish) was not identifiable in the published report. The RCT by Franks 2007 did not report the health-related quality of life outcomes that were pre-specified in the protocol and was classified as being at high risk of bias. The RCT by Vanscheidt 2004 was considered to be at high risk of selective reporting bias, as the published report indicated the use of scales to assess some outcomes that were not detailed in the protocol, the pre-specified outcome of patient-reported dressing leakage was not reported, and the cost of managing complications specified in the protocol was not included in the RCT report.

Overall risk of bias

Six of the included RCTs were considered as being at overall high risk of bias (Banerjee 1990; Callam 1992; Weiss 1996; Andersen 2002; Charles 2002; Franks 2007), as they were each rated as 'high' for one or more of three key domains (allocation concealment, blinding of outcome assessors and completeness of outcome data). The remaining six RCTs were classified as being at unclear risk of bias overall (Zuccarelli 1992; Bowszyc 1995; Thomas 1997; Vanscheidt 2004; Norkus 2005; Andriessen 2009), with three having 'unclear' ratings for all three key domains (Thomas 1997; Vanscheidt 2004; Norkus 2005). None of the RCTs was rated as having a low risk of bias overall.

Effects of interventions

See: Summary of findings for the main comparison polyurethane foam dressing compared to hydrocellular foam dressing for venous leg ulceration; Summary of findings 2 foam dressing compared to paraffin gauze dressing for venous leg ulceration; Summary of findings 3 foam dressing compared to hydrocapillary dressing for venous leg ulceration; Summary of findings 4 foam dressing compared to hydrocolloid dressing for venous leg ulceration; Summary of findings 5 foam dressing compared to knitted viscose dressing for venous leg ulceration

Twelve RCTs that evaluated foam dressings were included in this review. The results are presented according to the type of comparator dressing, starting with hydrocellular foam dressings compared with polyurethane foam dressings. This is followed by comparisons of foam dressings with: paraffin gauze dressings, hydrocapillary dressings, hydrocolloid dressings, knitted viscose dressings, and protease-modulating matrix dressings. Details of primary and secondary outcome data are presented in Table 1 and Table 2.

Table 1. Outcome data reported by included trials - primary (healing) outcomes
Andersen 2002

Time to healing weeks - mean (SD):

Group 1 (hydrocellular foam): 5.0 (1.7);

Group 2 (polyurethane foam): 5.2 (1.9).

 

Number (%) of ulcers healed at 8 weeks:

Group 1 (hydrocellular foam): 18/60 (30);

Group 2 (polyurethane foam): 18/58 (31).

 

Change in ulcer size – mean change in area cm2:

Group 1 (hydrocellular foam): -3.77;

Group 2 (polyurethane foam): -3.18.

P value for between-group difference not reported by trialists.

 

Change in ulcer size – mean percentage change in area (read from graph):

Group 1 (hydrocellular foam): -62%;

Group 2 (polyurethane foam): -64%.

P value for between-group difference not reported by trialists.

Andriessen 2009

Change in ulcer size – mean (range) percentage change in area at 4 weeks:

Group 1 (paraffin gauze): -17.2% (-31% to 4.6%);

Group 2: (protease-modulating matrix ): -31.8% (-28% to -34%);

Group 3 (polyurethane foam): -26.4% (-17.3% to -32%).

Comments: trialists reported that all participants were compliant with treatment.

Banerjee 1990

Number (%) of ulcers healed at 17 weeks:

Group 1 (paraffin gauze): 8/35 (23);

Group 2 (polyurethane foam): 11/36 (31).

 

Ulcer area cm2 at 17 weeks median (range):

Group 1 (paraffin gauze): 4.4 (0.2 to 22), n = 12;

Group 2 (polyurethane foam): 6.3 (0.2 to 108.2), n = 14.

Trialists did not report the change in ulcer size.

 

Change in ulcer area at 17 weeks cm2- difference in medians (calculated by review authors):

Group 1 (paraffin gauze): -7.0;

Group 2 (polyurethane foam): -5.9.

Bowszyc 1995

Time to healing weeks:

Group 1 (hydrocolloid): 9.34;

Group 2 (polyurethane foam): 10.50.

Not reported whether values are mean or median. Trialists reported P value = 0.35 for between-group difference.

 

Number (%) of legs healed at 16 weeks:

Group 1 (hydrocolloid): 24/41 legs (59);

Group 2 (polyurethane foam): 24/41 legs (59).

 

Comments: 7 participants were excluded due to protocol violations, 5 due to heavily-exuding wounds and 2 due to streptococcal cellulitis. Breakdown by group not reported, and not reported whether exclusion was pre- or post-randomisation. There were 8 cases of streptococcal cellulitis (4 in each group) that required antibiotic treatment; 2 participants were withdrawn from the trial as a result.

Callam 1992

Time to healing:

The reported P value for between-group difference in time to healing from a Cox survival model including the covariate of initial ulcer size was 0.08. No other data were reported.

 

Number (%) of ulcers healed at 12 weeks:

Group 1 (Knitted viscose): 23/66 (35);

Group 2 (hydrocellular foam): 31/66 (47).

 

Change in ulcer size:

Trialists reported a greater reduction in percentage ulcer area in Group 2 compared with Group 1, but the difference was not statistically significant at P value = 0.051. No average data were presented by group.

 

Percentage of ulcers with change in ulcer area - > 100% increase vs 50%-100% increase vs 0-50% increase vs 0-50% decrease vs 50%-100% decrease vs healed vs not known (read from graph):

Group 1 (Knitted viscose): 8% vs 8% vs 14% vs 15% vs 19% vs 35% vs 1%;

Group 2 (hydrocellular foam): 4% vs 4% vs 10% vs 12% vs 21% vs 47% vs 2%.

P value = 0.051 reported by trialists for between-group difference in ulcer area reduction.

Comments: trialists reported that initial or final ulcer tracing was not available for 3 patients.

Charles 2002

Mean time to healing weeks:

Group 1 (hydrocolloid, Comfeel): 6.0;

Group 2 (hydrocolloid, Granuflex): 7.5;

Group 3 (polyurethane foam): 7.0.

 

Number (%) of ulcers healed at 12 weeks:

Group 1 (hydrocolloid, Comfeel): 17/29 (59);

Group 2 (hydrocolloid, Granuflex): 17/31 (55);

Group 3 (polyurethane foam): 18/31 (58).

 

Change in ulcer size – mean percentage change in ulcer area:

Group 1 (hydrocolloid Comfeel): -82.1%;

Group 2 (hydrocolloid Granuflex): -83.6%;

Group 3 (polyurethane foam): -67.3%.

Trialists reported the percentage of ulcer area remaining, stating that the between-group difference was not statistically significant (P value not provided). The percentage change values presented here were extrapolated by the review authors.

Franks 2007

Number (%) of ulcers healed at 24 weeks:

Group 1 (polyurethane foam): 50/75 (66.7);

Group 2 (hydrocellular foam): 50/81 (61.7).

 

Cumulative healing rates at 12 weeks derived from Kaplan-Meier survival curves:

Group 1 (polyurethane foam): 50.7%;

Group 2 (hydrocellular foam): 47.5%.

 

Hazard ratio (95% CI) estimation from Cox proportional hazards model:

Initial model adjusted for dressings, bandages and study centres HR 1.48 (0.87 to 2.54), P value = 0.15.

Further model with additional adjustment for baseline covariates HR 1.50 (0.86 to 2.62), P value = 0.16.

Comment: in cases where the original ulcer closed but a new area developed on the same limb while the original ulcer was still present, the limb was considered to be open until this new area of ulceration had also closed (Franks 2004, see references listed under Franks 2007).

Norkus 2005

Time to healing:

Trialists reported that no statistically significant difference was found between Group 1 and Group 2 for time to healing, but no data by group, or P value for difference were presented. Unclear what analysis method was used (described as Kaplan-Meier principle).

 

Number (%) of ulcers healed at 12 months:

Group 1 (hydrocapillary): 25/49 (51);

Group 2 (polyurethane foam): 19/48 (40).

Thomas 1997

Number (%) of ulcers healed at 13 weeks:

Group 1 (hydrocolloid): 19/50 (38);

Group 2 (polyurethane foam): 17/50 (34).

 

Change in ulcer area - mean percentage change in ulcer area (read from graph):

Group 1 (hydrocolloid): -78%;

Group 2 (polyurethane foam): -88%.

Trial authors reported no statistically significant difference between groups, but no P value presented.

 

Number (%) participants with ulcers that reduced in area during trial period:

Group 1 (hydrocolloid): 34/50 (68);

Group 2 (polyurethane foam): 44/50 (88).

Vanscheidt 2004

Time to healing days - mean (SD):

Group 1 (hydrocolloid): 66 (3.4);

Group 2 (hydrocellular foam): 72.6 (3.1).

Trialists reported that there were no statistically significant between-group differences (P value = 0.47).

 

Number (%) of ulcers healed at 12 weeks:

Group 1 (hydrocolloid): 20/55 (36);

Group 2 (hydrocellular foam): 20/52 (38).

Slight discrepancy between text and table in trial report (values above taken from table). Text of report states proportion of ulcers healed in Group 1 38.2%, and Group 2 38.5%.

 

Healing rate - median change per week in cm2:

Group 1 (hydrocolloid): -0.41;

Group 2 (hydrocellular foam): -0.43.

Trialists reported that there were no statistically significant between-group differences (P value = 0.13).

 

Healing rate - median percentage change per week:

Group 1 (hydrocolloid): -7.3%;

Group 2 (hydrocellular foam): -6.1%,

Trialists reported that there were no statistically significant between-group differences (P value = 0.27).

Weiss 1996

Mean time to healing - weeks:

Group 1 (polyurethane foam): 5.6;

Group 2 (hydrocellular foam): 6.5.

 

Number (%) of ulcers healed at 16 weeks:

Group 1 (polyurethane foam): 8/10 (80);

Group 2 (hydrocellular foam): 4/8 (50).

 

Change in ulcer size -percentage change (dimension not stated) at week 3:

Group 1 (polyurethane foam): -27%;

Group 2 (hydrocellular foam): -13%.

P value for between-group difference not reported by trialists.

Zuccarelli 1992

Number (%) of ulcers healed at 12 weeks:

Group 1 (hydrocolloid): 9/19 (47);

Group 2 (hydrocellular foam): 9/19 (47).

Comment: trialists reported that the mean ulcer size in both groups reduced steadily throughout the trial, but no statistically significant between-group difference was observed (P value = 0.86).

Table 2. Outcome data reported by included trials - secondary outcomes
  1. Abbreviation

    VAS = visual analogue scale

Andersen 2002

Number (%) participants experiencing adverse events:

Group 1 (hydrocellular foam):

Maceration/erythema/secondary infected dermatitis, 1 (2).

Erysipelas, 1 (2).

Serious adverse event: hospitalisation (pain), 1 (2); hospitalisation (cardiovascular accident), 1 (2); death (acute myocardial infarction), 1 (2).

Group 2 (polyurethane foam):

Maceration/erythema/secondary infected dermatitis, 1 (2).

Pain after dressing change, 1 (2).

Allergic reaction (dermatitis), 1 (2).

Serious adverse event: no serious events reported.

The trialists reported that they could not verify a relationship between the dressings and the adverse events (resulting in withdrawal from the study).

 

Average material costs per participant per week:

Group 1 (hydrocellular foam): $ 18.99 ;

Group 2 (polyurethane foam): $ 10.87.

Included costs of dressings, unclear whether bandages and other treatment materials included, did not include nursing time, price year not stated, presumed currency is USD.

Mean number of dressing changes per week:

Group 1 (hydrocellular foam): 3.34;

Group 2 (polyurethane foam): 2.14.

The trialists reported a statistically significant difference (P value < 0.0005).

 

Pain at weekly assessments:

Group 1 (hydrocellular foam): no pain was recorded at 169/319 (53%) weekly assessments;

Group 2 (polyurethane foam): no pain was recorded at 226/379 (60%) weekly assessments.

P value for between-group differences not reported by trialists.

 

Pain - comfort of the dressing:

Participant ratings of comfort during treatment were reported as not significantly different between groups, but no data were presented.

 

Dressing performance - absorbency:

Group 1 (hydrocellular foam): dressing absorbency was rated as excellent in 12/170 (7%) of dressing changes;

Group 2 (polyurethane foam): dressing absorbency was rated as excellent in 124/163 (76%) of dressing changes.

The trialists reported a statistically significant difference (P value < 0.0005).

 

Dressing performance - leakage:

Group 1 (hydrocellular foam): leakage of exudate was observed in 198/309 (64%) of weekly assessments;

Group 2 (polyurethane foam): leakage of exudate was observed in 172/355 (48%) of weekly assessments.

The trialists reported a statistically significant difference (P value < 0.0005).

Andriessen 2009

Adverse events:

The trialists stated that no adverse events were reported.

 

Pain at dressing removal:

Group 1 (paraffin gauze): participants reported either moderate pain (mean VAS score of 4 to 6), or severe (mean VAS score of 7 to 9);

Group 2: (protease-modulating matrix  dressing): participants reported little or no pain (mean VAS score of 1 to 2);

Group 3 (polyurethane foam): participants reported little or no pain (mean VAS score of 1 to 2).

Trialists report that the paraffin gauze dressing stuck to the wound bed in 72% of the dressing changes (no report of this outcome for other treatment groups).

Banerjee 1990

Adverse events - number (%) participants died:

Group 1 (paraffin gauze): 3/35 (9);

Group 2 (polyurethane foam): 7/36 (19).

Adverse events - ulcer infection:

Trialists reported that there were no statistically significant differences between groups in the proportion of patients with infected ulcers at weeks 1, 4, 8, 12 or 17, but further details were not provided.

Pain:

Trialists reported that the ulcer pain score was similar across groups with no statistically significant difference, but no data were presented.

 

Number of dressing changes per week:

Trialists reported that more dressings and pads were used in Group 2 (polyurethane foam), but no data by group or P value for between-group differences were reported.

 

Number of visits for healed/unhealed ulcers - median:

Group 1: (paraffin gauze) 6.5/25.0;

Group 2: (polyurethane foam) 16.0/40.0.

The trialists reported the following P values for between-group differences: P < 0.05 for healed ulcers; and P < 0.002 for unhealed ulcers.

 

Nursing time spent per patient per week - median:

Group 1 (paraffin gauze): 4 hours 10 minutes

Group 2 (polyurethane foam): 5 hours 40 minutes

Trialists reported P value < 0.05 for between-group difference.

Bowszyc 1995

Number (%) patients experiencing adverse events:

Not reported in full. Trialists reported that complications of secondary infection and maceration occurred: there were 8 cases of streptococcal cellulitis which required antibiotic treatment (2 patients withdrew because of this). The same number of patients were affected in each group.

 

Costs:

UK Drug Tariff price per dressing (at October 1993) was reported as GBP 0.92 for 10 cm x 10 cm piece of foam dressing (Lyofoam) and GBP 2.08 for 10 cm x 10 cm piece of hydrocolloid dressing (Granuflex).

 

Pain - dressing comfort score, mean (SD):

Group 1 (hydrocolloid): 8.2 (2.5);

Group 2 (polyurethane foam): 8.7 (2.2).

Trialists reported no statistically significant between-group difference (P value not provided).

 

Pain score at dressing removal, mean (SD):

Group 1 (hydrocolloid): 3.63 (0.83);

Group 2 (polyurethane foam): 3.72 (0.55).

Trialists reported no statistical between-group difference (P value not reported).

 

Mean number of dressing changes per week in first month:

Group 1 (hydrocolloid): 1.5;

Group 2 (polyurethane foam): 1.6.

Trialists reported no statistically significant between-group difference (P value = 0.49).

 

Nurse-rated ease of removal – mean (SD) score from 11 point scale:

Group 1: (hydrocolloid) 1.42 (0.54);

Group 2 (polyurethane foam):  1.15 (0.42).

Trialists reported P value = 0.016 for between-group difference.

Callam 1992

Number (%) participants experiencing adverse events:

Group 1 (knitted viscose): no adverse reactions;

Group 2 (hydrocellular foam): local skin reaction, 2 (4).

Number (%) participants experiencing skin complications - sensitivity reaction to the dressing vs dry eczema vs wet eczema vs maceration vs other dressing complications (from supplied RCT report):

Group 1 (knitted viscose): 3/66 (5) vs 47/66 (71) vs 16/66 (24) vs 3/66 (5) vs 5/66 (8);

Group 2 (hydrocellular foam): 9/66 (14) vs 37/66 (56) vs 23/66 (35) vs 11/66 (17) vs 12/66 (18).

 

Pain at clinic visits:

Number (%) participants experiencing pain at 0% vs 1%-25% vs 26%-50% vs 51%-75% vs 76%-99% and 100% of clinic visits:

Group 1 (knitted viscose, n = 66 participants): 7 (11%) vs 8 (12%) vs 5 (8%) vs 5 (8%) vs 7 (11%) vs 34 (52%);

Group 2 (hydrocellular foam, n = 66 participants): 13 (20%) vs 6 (9%) vs 9 (14%) vs 12 (18%) vs 9 (14%) vs 17 (26%).

P value = 0.01 reported by trialists for between-group difference in patients experiencing pain during 100% of clinic visits.

Pain disturbing sleep:

Number (%) participants reporting pain disturbing sleep at 0% vs 1%-25% vs 26%-50% vs 51%-75% vs 76%-99% and 100% of clinic visits:

Group 1 (knitted viscose, n = 66 participants): 35 (53%) vs 16 (24%) vs 7 (11%) vs 1 (2%) vs 5 (8%) vs 2 (3%);

Group 2 (hydrocellular foam, n = 66 participants): 34 (52%) vs 17 (26%) vs 6 (9%) vs 4 (6%) vs 0 (0%) vs 5 (8%).

Charles 2002

Adverse events:

Trialists reported that no serious dressing-related adverse events were observed during the trial.

 

Pain – percentage of participants reporting ulcer pain at 12 weeks (read from graph):

Group 1 (hydrocolloid Comfeel): 8%;

Group 2 (hydrocolloid Granuflex): 4%;

Group 3 (polyurethane foam): 10%.

 

Pain - mean ulcer-associated VAS pain score at week 12:

Group 1 (hydrocolloid, Comfeel): 0.64, n = 28;

Group 2 (hydrocolloid, Granuflex): 0.15, n = 27;

Group 3 (polyurethane foam): 0.50, n = 30.

Trialists reported that between-group differences in pain prevalence and severity were not statistically significant at any point in the trial (P value not reported).

Change in mean scores (calculated by review authors):

Group 1 (hydrocolloid, Comfeel): -3.19;

Group 2 (hydrocolloid, Granuflex): -3.66;

Group 3 (polyurethane foam): -4.27.

Pain - proportion of patients reporting mid to lower-range pain severity on VAS and McGill Pain Questionnaire (MPQ-PPI) at week 12 (secondary reference Charles 2002 ):

Trialists reported that the number of participants reporting pain fell to < 10%. Unclear whether this was overall, or for a specific treatment group. No data by group presented.

Dressing performance - ease of use of dressings:

The foam dressing was significantly easier to remove compared with the two hydrocolloid dressings at 6 weeks and at last dressing (P value = 0.021 and P value = 0.037 respectively for the 2 time points; unclear how these P values relate to the between-group comparisons given there would be 2 comparisons at each time point).

Franks 2007

Number (%) participants experiencing adverse events:

Group 1 (polyurethane foam): 23/75 (30.7);

Group 2 (hydrocellular foam): 22/81 (27.2).

Trialists did not report the P value for between-group difference.

 

Category of dressing-related adverse event and number of occurrences:

Group 1 (polyurethane foam): not related to dressing = 21; possibly related to dressing = 4; definitely related to dressing = 11;

Group 2 (hydrocellular foam): not related to dressing = 15; possibly related to dressing = 4; definitely related to dressing = 11.

 

Number (%) participants who died during trial:

Group 1 (polyurethane foam):  0/75 (0);

Group 2 (hydrocellular foam):  1/81 (1.2).

 

Pre-dressing pain at week 4 (VAS) – median (interquartile range):

Group 1 (polyurethane foam): 1.5 (3.6), n = 53;

Group 2 (hydrocellular foam): 1.3 (3.7) n = 53.

The trialists reported P value = 0.18 for between-group difference.

 

Post-dressing pain at week 4 (VAS) – median (interquartile range):

Group 1 (polyurethane foam): 1.0 (2.0), n = 51

Group 2 (hydrocellular foam): 0.5 (1.8), n = 52

Trialists reported P value = 0.12 for between-group difference.

 

McGill Pain Questionnaire sensory pain scores at week 4 – median (interquartile range):

Group 1 (polyurethane foam): 2.0 (4.0), n = 47;

Group 2 (hydrocellular foam): 1.0 (3.0), n = 31.

Trialists reported P value = 0.40 for between-group difference.

 

McGill Pain Questionnaire affective pain scores at week 4– median (interquartile range):

Group 1 (polyurethane foam): 0.0 (0.0), n = 42;

Group 2 (hydrocellular foam): 0.0 (0.0), n = 47.

Trialists reported P value = 0.69 for between-group difference

 

Trialists reported that the levels of pain reduced significantly for both the VAS and McGill pain scores in both groups, however, the between-group differences at week 4 were not statistically significant.

Norkus 2005

Number (%) participants experiencing adverse events (type of adverse event):

Group 1 (hydrocapillary dressing): 8/49 (16%) (4 adverse events defined as related to dressing, of which: ulcer infection = 2, skin reactions = 2, description of other types of adverse events not provided). All 8 participants withdrew from the trial.

Group 2 (polyurethane foam): 11/48 (23%) (7 defined as related to dressing, of which: ulcer infections = 2, eczema = 3, allergic reaction = 1, peri-ulceration = 1, description of other types of adverse events not provided). All 11 participants withdrew from the trial.

 

Number (%) participants developing clinical signs of wound infection (all withdrew):

Group 1 (hydrocapillary dressing): 5/49 (10%);

Group 2 (polyurethane foam): 4/48 (8%).

It is unclear whether these participants with wound infection were also counted among those described above (adverse events).

 

Maceration: trialists reported that: 1 in 3 participants experienced some degree of maceration during the study; severe maceration was only reported in the polyurethane foam group (5%), and there were no significant between-group differences in maceration, however, no further data were provided, neither were P values.

 

Number of times that signs of allergy on peri-ulcer skin were reported:

Group 1 (hydrocapillary dressing): ;7

Group 2 (polyurethane foam): 16.

The trialists reported that allergic reactions were confirmed in 1 participant in each group by a positive patch test, and that there were no significant between-group differences in allergy.

 

Number of times that severe erythema was reported:

Group 1 (hydrocapillary dressing): 24 (1.7%);

Group 2 (polyurethane foam): 45 (3.3%),

Percentages as reported by trialists – denominators not stated. Trialists reported no significant between-group difference in erythema.

 

Quality of life – median WHO-5 Well-Being Index scores:

Group 1 (hydrocapillary): 68;

Group 2 (polyurethane foam): 68.

Trialists reported that there were no significant differences in the initial or final values between groups (P value not reported).

 

Wound pain between dressing changes:

Trialists reported that there was no significant difference in the incidence of wound pain between the 2 groups. Data by group and P value not reported.

 

Pain – number (%) assessing dressing comfort as good vs medium vs poor:

Group 1 (hydrocapillary): 42/43 (97.6) vs 1/43 (2.3) vs 0/43 (0);

Group 2 (polyurethane foam): 32/45 (71.1) vs 8/45 (17.8) vs 5/45(11.1).

Trialists reported that the comfort of the dressing in Group 1 was rated as significantly better than Group 2 (P value < 0.001).

 

Dressing performance, exudate handling – number (%) of incidents of little to moderate vs severe leakage at dressing change:

Group 1 (hydrocapillary): 139 (11) vs 1 (0.1);

Group 2 (polyurethane foam): 144 (13) vs 22 (2).

Trialists reported that no significant differences in leakage were found between the 2 treatment groups. Denominators not reported.

 

Trialists reported that the hydrocapillary dressing was rated by nurses as having a significantly better capacity to absorb exudate compared with the polyurethane foam (P value < 0.05 – no other data provided).

 

Dressing performance, adherence – number (%) dressing changes where dressing adherence to the wound was reported:

Group 1 (hydrocapillary dressing): 95/542 (18);

Group 2 (polyurethane foam): 113/388 (29).

Trialists reported P value < 0.05 for between-group difference.

 

Percentage of dressing changes (as reported by trialists) where adherence was rated as none vs little vs moderate vs severe:

Group 1 (hydrocapillary dressing): 82.5% vs 10.5% vs 6.6% vs 0.4%;

Group 2 (polyurethane foam): 70.9% vs 12.6% vs 13.1 % vs 3.4%.

 

Mean wear time of dressing, days:

Group 1 (hydrocapillary): 3.2;

Group 2 (polyurethane foam): 3.2.

Thomas 1997

Number (%) all participants (venous leg ulcers and pressure ulcers) experiencing adverse events linked to the dressing (described as due to adhesive nature of dressings causing minor trauma/erythema on removal):

Group 1 (hydrocolloid): 7/99 (7);

Group 2 (polyurethane foam): 10/100 (10).

Numbers by ulcer type not reported.

Number of participants with additional minor dressing related adverse events (venous leg ulcers only):

Group 1 (hydrocolloid): maceration = 6; bleeding from the wound bed = 1; excessive granulation = 3;

Group 2 (polyurethane foam): maceration = 0; bleeding from the wound bed = 0; excessive granulation = 0.

Pain - dressing comfort:

Trialists reported that Group 2 (polyurethane foam) was significantly more likely to be scored as comfortable (comfortable vs otherwise, P value = 0.023) at the first dressing change. No data by group were presented.

 

Number participants with wound dehydration and dressing adherence to wound (all wound types):

Group 1 (hydrocolloid): 0;

Group 2 (polyurethane foam): 2.

Group denominators not stated.

 

Dressing performance (exudate handling) – number (%) participants who had dressings removed at the first dressing change due to leakage:

Group 1 (hydrocolloid): 27/50 (54);

Group 2 (polyurethane foam): 7/50 (14).

Trialists reported that the between-group difference was statistically significant (P value < 0.0001).

Dressing performance - ease of removal:

Trialists reported that dressing removal in both treatment groups was rated by nurses as 'easy' in the majority of cases at the first dressing change. No data by group were presented.

 

Mean time the dressing was in place prior to the first change, days:

Group 1 (hydrocolloid): 2.7;

Group 2 (polyurethane foam): 2.8.

Vanscheidt 2004

Number (%) participants experiencing adverse events:

Group 1 (hydrocolloid): 13/55 (24) experienced 1 or more possibly dressing-related adverse event (19 events in total);

Group 2 (hydrocellular foam): 15/52 (29) experienced 18 possibly dressing-related adverse events.

 

Common adverse events and number of participants affected:

Group 1 (hydrocolloid): new wound development in different location = 6; other non-specific wound events (e.g. affecting participant wounds other than the study wound) = 5; reason not reported = 2;

Group 2 (hydrocellular foam): maceration = 6; new wound development in different location = 4; other non-specific wound events (e.g. affecting participant wounds other than the study wound) = 5.

Review authors' comment: numbers/types of adverse events per group were presented twice in the main text of the primary reference. Numbers of patients with different types of adverse events were discrepant between the 2 reports for Group 2.

Trialists reported no significant between-group difference (P value = 1.00, not clear if this referred to the difference in number of patients with adverse events or difference between total number of adverse events in group).

 

Serious adverse events and number of participants affected:

Group 1 (hydrocolloid): angina = 1; musculoskeletal = 1; died = 3;

Group 2 (hydrocellular foam): unspecified blood disease = 1.

 

Number (%) dressing changes with investigator-rated condition of peri-ulcer skin classified as normal vs maceration vs erythema vs eczema vs lipodermatosclerosis vs cellulitis vs dermatitis vs other:

Group 2 (hydrocolloid): 269/615 (44) vs 135/615 (22) vs 52/615 (8) vs 5/615 (1) vs 119/615 (19) vs 0/615 (0) vs 16/615 (3) vs 19/615 (3);

Group 1 (hydrocellular foam): 190/529 (36) vs 143/529 (27) vs 48/529 (9) vs 10/529 (2) vs 112/529 (21) vs 1/529 (<1) vs 16/529 (3) vs 9/529 (2).

Denominators are total number of dressing changes.

Trialists reported that no between-group differences were statistically significant, but no P value provided.

 

Pain at final assessment, number (%) with reduction in pain vs no effect on pain vs uncertain vs unable to respond/no response vs increased pain vs missing data:

Group 1 (hydrocolloid): 36/55 (65) vs 7/55 (13) vs 5/55 (9) vs3/55 (5) vs 4/55 (7) vs 0/55 (0);

Group 2 (hydrocellular foam): 21/52 (40) vs 15/52 (29) vs 4/52 (8) vs 0/52 (0) vs 9/52 (17) vs 3/52 (6).

Percentages for Group 2 recalculated by review authors to take account of missing data. Trialists reported that there were no statistically significant between-group differences (P value = 0.10).

Dressing performance (exudate handling) – number (%) participants with minimal or moderate levels of exudate at dressing change:

Group 1 (hydrocolloid): 43/55(79);

Group 2 (hydrocellular foam): 43/52 (83).

Trialists reported that the between-group difference was not statistically significant but P value not provided.

 

Dressing performance (exudate handling) – number (%) dressing changes with no exudate vs minimal exudate (< 25% of dressing saturated) vs moderate exudate (25%-75% of dressing saturated) vs considerable exudate (> 75% of dressing saturated):

Group 1 (hydrocolloid): 51/615 (8) vs 204/615 (33) vs 234/615 (38) vs 126/615 (20);

Group 2 (hydrocellular foam): 42/529 (8) vs 199/529 (38) vs 196/529 (37) vs 89/529 (17).

Trialists reported that the between-group difference was not statistically significant but P value not provided.

 

Mean (SD) number of dressing changes per week:

Group 1 (hydrocolloid): 11.4 (6.5);

Group 2 (hydrocellular foam): 10.1 (6.3).

Trialists reported that the between-group difference was not statistically significant but P value not provided. 

Mean (SD) dressing wear time days:

Group 1 (hydrocolloid): 5.6 (1.3);

Group 2 (hydrocellular foam): 5.6 (1.2).

Trialists reported that the between-group difference was not statistically significant but P value not provided.

 

Dressing performance - percentage of participants who rated non-traumatic dressing removal categories of excellent/very good vsgood vsfair or poor (read from graph):

Group 1 (hydrocolloid): 84% vs 11% vs 5% vs 0%

Group 2 (hydrocellular foam): 68% vs 22% vs 4% vs 6%

Trialists reported P value = 0.07 for between-group differences.

Dressing performance - percentage of participants who rated ease of removal categories of excellent/very good vs good vs fair vs poor (read from graph):

Group 1 (hydrocolloid): 84% vs 10% vs 4% vs 2%;

Group 2 (hydrocellular foam): 74% vs 18% vs 6% vs 2%.

Trialists reported P value = 0.19 for between-group differences.

Weiss 1996

Number (%) patients experiencing adverse events (type of adverse event):

Group 1 (polyurethane foam): 0/10 (0);

Group 2 (hydrocellular foam): 1/8 (38) - allergic reaction which necessitated withdrawal.

 

Pain reduction and dressing comfort:

Trialists stated that all participants reported a great reduction in pain, and that participants in Group 1 (polyurethane foam) preferred the comfort of the dressing. No data by group were presented.

Zuccarelli 1992

Number (%) patients experiencing adverse events:

Group 1 (hydrocolloid): 2/19 (11) showed an allergic reaction and an intolerance in the peri-ulcer skin area in the form of blisters;

Group 2 (hydrocellular foam): no unwanted side effects were reported.

 

Mean (SD) number of dressing changes per week:

Group 1 (hydrocolloid): 26.9;

Group 2 (hydrocellular foam): 19.5

Trialists reported that the between-group difference was not significant (P value = 0.14).

 

Mean pain scores over the course of treatment:

Group 1 (hydrocolloid dressing): scores decreased during the first 2 weeks of treatment (P value = 0.005 for within group difference over time), increased slightly in the third week and then stabilised from then on.

Group 2 (hydrocellular foam dressing): scores decreased during the first week of treatment (P value = 0.005 for within group difference over time) and remained stable from then on.

Trialists reported no significant difference between groups.

 

Mean pain score at 12 weeks (read from graph):

Group 1 (hydrocolloid): 1.5;

Group 2 (hydrocellular foam): 1.7.

Trialists reported that the between-group difference was not significant (P value = 0.52).

Change in mean scores (calculated by review authors from graph):

Group 1 (hydrocolloid): -0.8;

Group 2 (hydrocellular foam): -0.9.

Hydrocellular foam dressings compared with polyurethane foam dressings

Three RCTs recruiting a total of 295 participants were identified that compared a hydrocellular foam dressing with a polyurethane foam dressing (Weiss 1996; Andersen 2002; Franks 2007). 

Primary outcomes
Time to complete ulcer healing

Weiss 1996 randomised eight participants to a hydrocellular foam dressing (Allevyn) and ten to a polyurethane foam dressing (Cutinova). All participants received compression therapy in the form of graduated compression stockings. The trialists reported a mean time to healing of 6.5 weeks in the hydrocellular foam group compared with 5.6 weeks in the polyurethane foam group. No variance data or P value for the between-group difference was reported. This RCT was considered to be at overall high risk of bias as it was described as a non-blinded evaluation. This RCT was a pilot study with a small sample size.

Andersen 2002 randomised 60 participants to receive a hydrocellular foam dressing (Allevyn) and 58 to receive a polyurethane foam dressing (Biatain). Short-stretch compression bandaging was used. Participants were assessed every seven days until the ulcer was completely healed or the trial period (eight weeks) was completed. It should be noted that the median baseline ulcer duration was longer in the group receiving the hydrocellular foam dressing. The mean (SD) time to healing in the hydrocellular foam dressing group was 5.0 (1.7) weeks (n = 46) compared with 5.2 (1.9) weeks (n = 53) in the polyurethane foam dressing group. A P value for the between-group difference was not reported by the trialists. This RCT was judged to be at overall high risk of bias as the RCT was described as not blinded and participants who withdrew were not included in the final analysis.

Franks 2007 randomised 81 participants to receive a hydrocellular foam dressing (Allevyn) and 75 to receive a silicone-faced polyurethane foam dressing (Mepilex). The factorial design of the RCT also allowed evaluation of two compression systems (four-layer bandage versus short-stretch bandage). Approximately 50% of participants in each randomised dressing group were randomised to each of the two compression bandaging systems. The cumulative healing rates at 12 weeks derived from Kaplan-Meier survival curves were 47.5% in the hydrocellular foam group compared with 50.7% in the polyurethane group. The hazard ratio (95% CI) estimation for healing derived from a Cox proportional hazards model adjusted for baseline covariates (ulcer size, ulcer duration and participant mobility) did not suggest a statistically significant difference between treatment groups: 1.50 (0.86 to 2.62), P value 0.16. The hazard ratio is an expression of the hazard (chance) of an event (e.g. ulcer healing) occurring in one treatment group as a ratio of the hazard of the event occurring in the other group. These results reported by Franks 2007 can be interpreted as an absence of a statistically significant difference between the hydrocellular foam dressing group and the polyurethane foam dressing group in the rate at which ulcers healed over the course of the trial, irrespective of variations in treatment delivery or participant characteristics. This RCT was considered to be at overall high risk of bias, as the outcome assessment was not blinded.

Proportion of ulcers completely healed

All three RCTs reported this outcome (Weiss 1996; Andersen 2002; Franks 2007). 

In the RCT by Andersen 2002, the number of ulcers healed at eight weeks was 18/60 (30%) in the hydrocellular foam dressing group compared with 18/58 (31%) in the polyurethane foam dressing group. The between-group difference was not statistically significant (RR 1.03, 95% CI 0.60 to 1.78) (Analysis 1.1). 

Weiss 1996 reported that the number of ulcers completely healed at 16 weeks was 8/10 (80%) in the polyurethane foam group compared with 4/8 (50%) in the hydrocellular foam group. The between-group difference was not statistically significant (RR 1.60, 95% CI 0.75 to 3.42) (Analysis 1.1).

Franks 2007 reported that the proportion of ulcers healed at 24 weeks was 50/81 (61.7%) in the hydrocellular foam dressing group compared with 50/75 (66.7%) in the polyurethane foam dressing group. The between-group difference in was not statistically significant (RR 1.08, 95% CI 0.85 to 1.37) (Analysis 1.1).

A pooled estimate of effect across these RCTs was not undertaken because of variation in follow up periods.

Change in ulcer size

Weiss 1996 reported the percentage reduction in ulcer size at week three of the 16-week RCT, but did not report the dimension (area, length/width, diameter or circumference). The percentage reduction was 27% in the hydrocellular foam group compared with 13% in the polyurethane foam group. No variance data were reported. The trialists did not report a P value for the between-group difference.

Andersen 2002 reported that the mean reduction in ulcer area at eight weeks was 3.77 cm2 in the hydrocellular foam group compared with 3.18 cm2 in the polyurethane foam group. No variance data were reported. The percentage reduction in ulcer area (read from graph) was 62% in the hydrocellular foam group compared with 64% in the polyurethane foam group. The trialists did not report a P value for the between-group differences for either the absolute or relative change. 

Secondary outcomes
Adverse events

Weiss 1996 recorded the incidence of an allergic reaction and reported that 1/8 (38%) participants in the hydrocellular foam group experienced an allergic reaction (type not specified) that necessitated withdrawal from the RCT. The RCT report contained no statement regarding adverse events with respect to the polyurethane foam group.

Andersen 2002 assessed peri-ulcer skin reactions using a verbal rating scale (VRS) and reported that 2/60 (3%) participants in the hydrocellular foam group and 3/58 (5%) participants in the polyurethane foam group experienced adverse events. These included maceration, erythema, secondary infected dermatitis, erysipelas, allergic reaction and pain at dressing change; some participants experienced more than one type of adverse event. Two out of the 60 participants in the hydrocellular foam group were hospitalised and one died; these were classified by the trialists as serious adverse events. No serious adverse events were reported in the polyurethane foam group.

Franks 2007 stated that 22/81 (27%) participants in the hydrocellular foam group reported 30 adverse events compared with 23/75 (31%) reporting 23 adverse events in the polyurethane foam group. Fifteen adverse events in each group were deemed as being possibly, or definitely, dressing-related. The trialists also reported that one participant in the hydrocellular foam group died compared with none in the polyurethane foam group. The RR estimate for the number of participants experiencing adverse events did not indicate a statistically significant difference between groups: RR 1.13 (95% CI 0.69 to 1.85), Analysis 1.2.

Pooling of data was not undertaken because of the diversity of the nature of adverse events, methods of assessment, and reporting across the three RCTs.

Cost: material costs

Andersen 2002 reported that the average material costs per participant per week was 18.99 dollars in the hydrocellular foam group compared with 10.87 dollars in the polyurethane foam group (type of dollars and price year not reported). The estimation included the cost of dressings (though it was unclear whether bandages and other treatments were included), but excluded nursing time. No variance data were reported. The trialists did not report a P value for the between-group difference.

Cost: number of dressing changes

Andersen 2002 reported that the mean number of dressing changes per week was 3.34 in the hydrocellular foam group compared with 2.14 in the polyurethane foam group. No variance data were reported. The trialists reported a statistically significant between-group difference (P value < 0.0005).

Pain

Weiss 1996 reported that all participants experienced a reduction in pain and stated that the participants in the polyurethane foam group preferred the comfort of the dressing (but what they were asked to compare it to was not clear). The method of assessment was not reported, and no data by group were presented.

In the RCT by Andersen 2002, participants were asked to report ulcer pain during weekly assessments. No pain was recorded for the hydrocellular foam group during 169/319 (53%) weekly assessments compared with 226/379 (60%) weekly assessments in the polyurethane foam group. The P value for the between-group difference was not reported by the trialists.

Franks 2007 reported median scores with inter-quartile ranges at four weeks for pre- and post-dressing pain derived from a visual analogue scale (VAS) and sensory pain and affective pain from the McGill pain questionnaire. The levels of pain reduced significantly for both the VAS and McGill pain scores in both groups, however, the between-group differences at week four were not statistically significant. No variance data were reported.

Dressing performance: exudate management

Andersen 2002 reported that dressing absorbency, assessed by recording the incidence of leakage, was rated as excellent in 12/170 (7%) of dressing changes in the hydrocellular foam group compared with 124/163 (76%) of dressing changes in the polyurethane foam group. The trialists reported a statistically significant between-group difference (P value < 0.0005). Leakage of exudate was observed in 198/309 (64%) of weekly assessments in the hydrocellular foam group compared with 172/355 (48%) of weekly assessments in the polyurethane foam group. The trialists reported a statistically significant between-group difference (P value < 0.0005).

Hydrocellular foam dressings compared with polyurethane foam dressings: summary of results

Evidence from three RCTs indicated that there was no statistically significant difference between hydrocellular foam dressings and polyurethane foam dressings in the proportion of ulcers completely healed at 8, 16 or 24 weeks (Weiss 1996; Andersen 2002; Franks 2007). One of these RCTs was a pilot study with a small sample size (Weiss 1996) and all three were considered to be at overall high risk of bias.

One RCT reported an adjusted hazard ratio estimate suggesting that there was no statistically significant difference between treatment groups in terms of probability of healing over the 24-week study period (Franks 2007). Data from the same RCT indicated no statistically significant difference between groups for the proportion of participants experiencing adverse events. Insufficient data were provided for the review authors to calculate measures of treatment effect for other outcomes, however, it is possible that polyurethane foam dressings perform better than hydrocellular foam dressings for exudate handling, and that pain scores are similar for the two dressings.

Paraffin gauze dressings compared with foam dressings

Two RCTs were identified that compared a paraffin-impregnated gauze dressing with a hydrocellular foam dressing (Banerjee 1990; Andriessen 2009). 

Primary outcomes
Proportion of ulcers completely healed

In the RCT by Banerjee 1990, 35 participants were randomised to receive a paraffin gauze dressing (Paratulle) and 36 were randomised to receive a polyurethane foam dressing (Synthaderm). The report provided no details about the use of compression therapy. The length of treatment was 17 weeks, or until the ulcer healed. More participants allocated to the paraffin gauze dressing group had mobility problems, and more participants allocated to the foam dressing group had infected ulcers. At 17 weeks 8/35 (23%) ulcers had healed in the paraffin gauze group compared with 11/36 (31%) in the polyurethane foam group. The between-group difference was not statistically significant (RR 1.34, 95% CI 0.61 to 2.92) (Analysis 2.1). This RCT was considered to be at overall high risk of bias, as, in addition to participants reported as withdrawing, a number of other participants appeared to be missing from the final analysis. 

Change in ulcer size

In one RCT, the change in median ulcer area from baseline to 17 weeks (estimated by the review authors from information provided in the RCT report) was -7.0 cm2 in the paraffin gauze group compared with -5.9 cm2 in the polyurethane foam group (Banerjee 1990). The other RCT was a three-arm pilot study allocating 12 participants to receive one of three dressings: paraffin gauze (proprietary name not reported); polyurethane foam (Suprasorb P); and protease-modulating matrix (Suprasorb C). All participants wore short-stretch high compression bandages. The length of treatment was four weeks. The trialists reported that, as this was a pilot study, the sample size was not based on statistical considerations. The mean percentage change in ulcer area (range) at four weeks was -17.2% (-31% to 4.6%) in the paraffin gauze group compared with -26.4% (-17.3% to -32%) in the polyurethane foam group. No other variance data were reported. The trialists did not report a P value for the between-group difference. The comparison between foam and protease-modulating matrix dressings was reported in a later section (Andriessen 2009).

Secondary outcomes
Adverse events

Banerjee 1990 reported that 3/35 (9%) of participants in the paraffin gauze group and 7/36 (19%) of participants in the polyurethane foam group died during the course of the RCT. Andriessen 2009 reported that no adverse events were recorded during the RCT.

Cost: number of dressing changes

Banerjee 1990 reported that more dressings and pads were used in the polyurethane foam group than the paraffin gauze group, but did not report data by group, or a P value for between-group differences. 

Cost: nursing time

Banerjee 1990 reported that the nursing time spent per patient per week was five hours 40 minutes in the polyurethane foam group compared with four hours 10 minutes in the paraffin gauze group (not reported whether these values were means or medians). The trialists reported a P value of < 0.05 for the between-group difference.

Pain

Banerjee 1990 assessed ulcer pain weekly on a four-point scale (details of scale not reported), reporting that the score was similar across groups with no statistically significant difference, however, no data were presented. Andriessen 2009 recorded pain at each dressing removal on a 10 cm visual analogue scale (VAS). In the paraffin gauze group participants reported either moderate (mean VAS score of 4 to 6) or severe (mean VAS score of 7 to 9) pain at dressing removal, whereas in the polyurethane foam group participants reported little or no pain (mean VAS score of 1 to 2).

Dressing performance: adherence to the wound bed

Andriessen 2009 reported that the paraffin gauze dressing stuck to the wound bed in 72% of the dressing changes. The number of dressing changes was not reported for the polyurethane foam group.

Paraffin gauze dressings compared with foam dressings: summary of results

Evidence from one RCT indicated no statistically significant between-group difference in foam dressings compared with paraffin gauze dressings in the proportion of ulcers completely healed at 17 weeks (Banerjee 1990); this RCT was considered to be at overall high risk of bias. Otherwise, data were limited and measures of treatment effect could not be estimated for other outcomes.

Hydrocapillary dressings compared with foam dressings

We identified one RCT that compared a hydrocapillary dressing with a foam dressing (Norkus 2005).  Hydrocapillary dressings are designed to act as a wick so that exudate is drawn away from the wound surface. The dressing evaluated by Norkus 2005 (Alione adhesive, Coloplast) comprises a hydrocapillary pad surrounded by a hydrocolloid adhesive, which exposes a non-adherent ulcer contact layer, covered by a water-resistant, bacteria-proof, semipermeable top film (Morris 2003).

Primary outcomes
Time to complete ulcer healing

Norkus 2005 randomised 49 participants to receive a hydrocapillary dressing (Alione) and 48 participants to receive two polyurethane foam dressings sequentially: one at the start of the RCT (Tielle plus) followed by the other (Tielle) when dressing changes were required less frequently. Thirty-six of the 49 participants receiving the hydrocapillary dressing (73%) and 32 of the 48 participants receiving the foam dressings (67%) received compression therapy during the RCT (type not reported). Ulcers were treated until they healed, or for a maximum of 12 months. The trialists reported that no significant differences were found between the two treatment groups for time to healing, but did not present data by group or a P value for the between-group difference, and the analysis method was unclear.

Proportion of ulcers completely healed

Norkus 2005 reported that 25/49 (51%) ulcers had healed at 12 months in the hydrocapillary dressing group compared with 19/48 (40%) ulcers in the polyurethane foam group. The between-group difference was not statistically significant (RR 0.78, 95% CI 0.50 to 1.21) (Analysis 3.1). The sample comprised participants with ulcers of venous, mixed or other aetiology and wounds with medium and high levels of wound exudate. Participants receiving the hydrocapillary dressing had larger and more chronic ulcers at baseline compared with those in the polyurethane foam group (median values provided). 

Secondary outcomes
Adverse events

In the RCT by Norkus 2005, research nurses assessed adverse events (odour, maceration, leakage, erythema and eczema) on a four-point scale (none, mild, moderate or severe). In the hydrocapillary dressing group 8/49 (16%) experienced adverse events (four were defined as related to the dressing: two ulcer infections and two skin reactions; however, the remaining four participants’ adverse events were not described), compared with 11/48 (23%) in the polyurethane foam group (seven were defined as related to the dressing: two ulcer infections, three eczema, one allergic reaction, and one peri-ulceration). The between-group difference was not statistically significant (RR 1.40, 95% CI 0.62 to 3.18) (Analysis 3.2). All participants experiencing these adverse events withdrew from the RCT.

Five out of 49 participants (10%) in the hydrocapillary dressing group and 4/48 (8%) participants in the polyurethane foam group developed clinical signs of wound infection (all withdrew), but it was unclear whether any of the participants developing wound infection were amongst those withdrawing due to other adverse events. The trialists reported that one in three participants experienced some degree of maceration during the RCT, that severe maceration was only reported in the polyurethane foam group (5%), but that there were no significant between-group differences in maceration, but did not report further data or P values. The trialists reported that there were 24 (1.7%) occurrences of severe erythema in the hydrocapillary dressing group compared with 45 (3.3%) in the polyurethane foam group, however, it was unclear whether these occurrences referred to dressing changes or something else, as the denominator was not reported. The trialists reported no significant between-group difference.

Health related quality of life

Norkus 2005 assessed health related quality of life at the start and the end of the RCT using the WHO-5 Well-being Index. Responses to five questions were scaled from 0 to 5 and the total multiplied by four to give a maximum 100 value (the higher the score, the better the participant’s well being). At baseline, the median scores were 60 for the hydrocapillary dressing group and 48 in the polyurethane foam group; both groups achieved a median score of 68 at 12 months. The trialists reported that there were no significant differences in the initial or final values between-groups (P value not reported).

Cost: wear time

Norkus 2005 reported that the estimated mean wear time was 3.2 days for both dressing groups, however, no other data were presented for this outcome.

Pain

In the RCT by Norkus 2005 wound pain at dressing removal, and at assessment visits between dressing changes, was reported by participants on a four-point scale (none, mild, moderate or severe). There was no significant difference in the incidence of wound pain between the two groups, however, data by group and P-values were not reported

Dressing performance: exudate management and adherence to the wound bed

In the RCT by Norkus 2005 dressing absorption was measured on a three-point scale (good, moderate or poor). The RCT personnel were asked to estimate additional wear time based on saturation of the dressing. Adherence of the dressing to the wound bed was also assessed. The trialists reported that no significant differences in the incidence of little to moderate and severe leakage at dressing change were found between the two treatment groups, but that there was a significant difference in favour of the hydrocapillary dressing in the number dressing changes in which the dressing adhered to the wound. There was a discrepancy in the RCT report, however, regarding the denominator (the number of dressing changes) for these two outcomes, and it was unclear what the total number of dressing changes should have been in the RCT. 

Hydrocapillary dressings compared with foam dressings: summary of results

Evidence from one RCT indicated that there was no statistically significant difference between foam dressings and hydrocapillary dressings in the proportion of ulcers completely healed at 12 months (Norkus 2005). This RCT was considered to have an overall unclear risk of bias.

Evidence from the same RCT indicated that there was no statistically significant difference between foam dressings and hydrocapillary dressings in the number of people who experienced adverse events (Norkus 2005). Insufficient data were available to estimate treatment effects for other outcomes.

Hydrocolloid dressings compared with foam dressings

We identified five RCTs that compared hydrocolloid dressings with foam dressings (Zuccarelli 1992; Bowszyc 1995; Thomas 1997; Charles 2002; Vanscheidt 2004).

Primary outcomes
Time to complete ulcer healing

Time to complete ulcer healing was reported in three RCTs that compared a hydrocolloid dressing with a foam dressing (Bowszyc 1995; Charles 2002; Vanscheidt 2004).

Bowszyc 1995 randomised 40 participants to a hydrocolloid dressing and 40 participants to a polyurethane foam dressing. A high-compression elastic bandage was used with both dressings. The length of treatment was 16 weeks, or until the ulcer had healed. The trialists reported that the time to healing was 10.50 weeks in the foam group, compared with 9.34 weeks in the hydrocolloid group. The trial report did not state whether these values were means or medians. The trialists reported a P value of 0.35 for the between-group difference. This RCT was considered to be at overall unclear risk of bias.

The RCT by Charles 2002 was a three-armed RCT with 31 participants randomised to receive one hydrocolloid dressing (Granuflex), 29 participants randomised to receive another hydrocolloid dressing (Comfeel), and 31 who were randomised to a polyurethane foam dressing. All participants received short-stretch compression bandaging. Length of treatment was 12 weeks, or until the ulcer healed. The trialists reported that the mean time to healing was 7.5 weeks and 6.0 weeks respectively in the two hydrocolloid groups, compared with 7.0 weeks in the polyurethane foam group. The trialists did not report the P value for between-group difference, nor variance data. This RCT was considered to be at an overall high risk of bias.

Vanscheidt 2004 randomised 55 participants to receive a hydrocolloid dressing and 52 participants to receive a hydrocellular foam dressing. All participants received a high-compression elastic bandage. Length of treatment was 12 weeks, or until healing of the ulcer occurred. The mean (SD) time to healing was reported as 66.0 (3.4) days in the hydrocolloid group compared with 72.6 (3.1) days in the foam dressing group; trialists reported a P value of 0.47 for the between-group difference. This RCT was considered as being at unclear risk of bias overall.

Proportion of ulcers completely healed

Three of the RCTs evaluating hydrocolloid dressings compared with foam dressings reported number of ulcers healed at 12 weeks (Zuccarelli 1992; Charles 2002; Vanscheidt 2004).

Zuccarelli 1992 randomised 19 participants to receive a hydrocolloid dressing and 19 to receive a hydrocellular foam dressing. Compression therapy was in the form of a two-layer system. This first layer was kept in place, whereas the second layer was removed by the participant before going to bed and re-applied before getting up in the morning. The length of treatment was 12 weeks. At the end of the 12 weeks 9/19 (47%) ulcers had healed in both the hydrocolloid dressing group and the hydrocellular foam dressing group. 

Charles 2002 reported that 17/29 (59%) ulcers in the Comfeel hydrocolloid dressing group and 17/31 (55%) in the Granuflex hydrocolloid dressing group had healed at 12 weeks, compared with 18/31 (58%) ulcers in the polyurethane foam group.

The number of ulcers that healed at 12 weeks in the hydrocolloid group in the RCT by Vanscheidt 2004 was 20/55 (36%) compared with 20/52 (38%) in the hydrocellular foam group. 

Thomas 1997 randomised 50 participants to receive a hydrocolloid dressing and 50 to receive a polyurethane foam dressing. All participants received compression consisting of orthopaedic padding plus a high compression elastic bandage. The number of ulcers healed at 13 weeks in the hydrocolloid dressing group was 19/50 (38%) compared with 17/50 (34%) in the polyurethane foam group.

One RCT comparing a hydrocolloid dressing with a foam dressing reported the number of legs healed at 16 weeks (Bowszyc 1995). Bowszyc 1995 reported that 24/41 (59%) legs had healed at 16 weeks in the group receiving the hydrocolloid dressing compared with 24/41 (59%) legs in the group receiving the polyurethane foam dressing. The trialists reported that two of the 80 participants who were randomised had bilateral leg ulcers (one in each group), however, they did not report how many participants in each of the two groups had healed at 16 weeks.

We compared each of the hydrocolloid dressings evaluated by Charles 2002 in separate pooled analyses. The pooled estimates for the between-group difference in complete ulcer healing from 12 to 16 weeks across the five RCTs were not statistically significant (including the Charles 2002 Comfeel group, RR 0.99, 95% CI 0.80 to 1.22; including the Charles 2002 Granuflex group, RR 1.00, 95% CI 0.81 to 1.24) (Analysis 4.1). Clinical advice was sought as to whether the two hydrocolloid dressings evaluated by Charles 2002 were similar enough to combine into a single treatment group for analysis (the method is detailed in the Cochrane Handbook Chapter 16.5 Higgins 2011b); this was confirmed as being appropriate. The pooled estimate for the between-group difference across the five RCTs was not statistically significant (RR 1.00, 95% CI 0.81 to 1.22) (Analysis 4.1) (Figure 4). There was no evidence of statistically significant heterogeneity, the Chi2 P value being 0.99 and I2 estimation 0% for all three meta-analyses.

Figure 4.

Forest plot of comparison: 4 Hydrocolloid compared with foam, outcome: 4.1 Proportion of ulcers completely healed at 12 to 16 weeks.

Change in ulcer size

Two RCTs reported the mean percentage change in ulcer area at final follow up (Thomas 1997; Charles 2002). Thomas 1997 presented mean change estimates at 13 weeks of -78% for the group receiving the hydrocolloid dressing and -88% for those allocated foam (read from figure). Reviewer-extrapolated estimates from Charles 2002 at 12 weeks were as follows: hydrocolloid (Comfeel) -82.1%; hydrocolloid (Granuflex) -83.6%; and foam dressing -67.3%. Both RCT reports indicated that differences between groups were not statistically significant, but no P values were provided.

Healing rate

Two RCTs mentioned undertaking assessment of healing rates (Zuccarelli 1992; Vanscheidt 2004). One presented only minimal information (Zuccarelli 1992), and reported that the mean ulcer size in both groups reduced steadily throughout the RCT, but no statistically significant between-group difference was observed (P value 0.86). No rate of healing data by group were reported. Data from the second RCT indicated similar median rates of healing for hydrocolloid and foam dressings, respective values being -0.41 cm2/week and -0.43 cm2/week. The respective values for median percentage healing rates per week were -7.3% and -6.1%. The trial authors reported P values of 0.13 and 0.27 respectively, for the between-group differences (Vanscheidt 2004).

Secondary outcomes
Adverse events

Zuccarelli 1992 did not report how adverse events were assessed, but reported that 2/19 (11%) participants in the hydrocolloid group experienced an allergic reaction and an intolerance in the peri-ulcer skin area in the form of blisters, whereas no unwanted side effects were reported in the hydrocellular foam group.

Bowszyc 1995 reported that complications of secondary infection and maceration occurred, and that there were eight cases of streptococcal cellulitis that required antibiotic treatment (two participants withdrew because of this). Whilst the trialists reported that the same number of participants were affected in each group, they did not report the number of participants experiencing adverse events by treatment group. Furthermore, they did not describe the method of assessment of adverse events and it was unclear whether adverse events other than maceration or cellulitis had occurred.

Thomas 1997 reported that 7/99 (7%) participants in the hydrocolloid group and 10/100 (10%) in the foam group experienced adverse events related to the adhesive nature of the dressing such as minor trauma or erythema (skin redness); this report related to the overall sample of participants with leg ulcers and pressure ulcers and was not broken down by wound type. Additional adverse events noted by the trialists included maceration, bleeding from the wound area and excessive granulation; of those with leg ulcers, these affected six, one and three participants respectively in the hydrocolloid group, and none in the foam group.

The RCT by Charles 2002 did not describe how, or which, adverse events were assessed, but reported that no serious dressing-related adverse events were observed during the RCT.

Vanscheidt 2004 recorded dressing-related adverse events and severe adverse events deemed unrelated to the dressing, together with descriptions. In the hydrocolloid group 13/55 (24%) participants experienced one or more possible dressing-related adverse event (19 events in total) compared with 15/52 (29%) participants in the hydrocellular foam group who experienced 18 possible dressing-related events. The between-group difference in participants experiencing adverse events was not statistically significant (RR 1.22, 95% CI 0.64 to 2.31) (Analysis 4.2). The trialists also reported on the occurrence of common adverse events (e.g. maceration, new wound development in different location, and non-specific wound events), however, there were discrepancies between the numbers reported in the primary and secondary references. The trialists reported no statistically significant between-group difference (P value 1.00), but it was not clear from the report if the difference referred to the number of participants with adverse events or the difference between the total number of adverse events in each group.

The adverse events assessment and reporting across these RCTs was considered too diverse for statistical pooling of data.

Pain

Zuccarelli 1992 evaluated pain using a numeric scale with lower scores representing less pain. Methods for collecting these data were not described. Data were presented graphically, using a range from 1.3 to 2.7 (full range of scores not stated). Reading from the graph, the mean pain score at week 12 was 1.5 in the group receiving the hydrocolloid dressing compared with 1.7 in the group receiving the hydrocellular foam dressing. No variance data were reported. The respective changes in mean scores from baseline (calculated from graph by review authors) were -0.8 and -0.9. The trialists reported that during the RCT there was a significant pain reduction in both dressing groups (P value 0.005) but that the between-group difference was not statistically significant (P value 0.52).

Bowszyc 1995 assessed ulcer pain at dressing removal on a scale of 1 to 4 (1 = very painful and 4 = no pain) at the end of the RCT. The trialists reported a mean pain score (SD) of 3.63 (0.83) in the group receiving the hydrocolloid dressing compared with a mean score of 3.72 (0.55) in the group receiving the polyurethane foam dressing. The trialists reported that the between-group difference was not statistically significant (P value not reported). The mean change in scores from baseline with variance estimate was not reported.

Charles 2002 reported ulcer-associated pain using a 10-point visual analogue scale with lower scores indicating less pain. The mean score at the week 12 follow up was 0.64 in the hydrocolloid Comfeel dressing group (n = 28), 0.15 in the hydrocolloid Granuflex dressing group (n = 27), and 0.50 in the polyurethane foam group (n = 30). No variance data were reported. The changes in mean scores from baseline (calculated by review authors) were -3.19, -3.66 and -4.27 respectively. The trialists reported that between-group differences in pain prevalence and severity were not statistically significant at any point in the RCT (P value not reported).

In the RCT by Vanscheidt 2004, the number of participants with a reduction in pain, no effect on pain, uncertain effect, unable to respond/no response, increased pain, and those with missing data were reported for the final assessment (data were collected using the Johns Hopkins Pain Rating Instrument). The trialists reported that there were no statistically significant between-group differences (P value 0.10 for overall effect of dressing on participant-reported ulcer pain).

Due to the varied assessment methods and outcome reporting of pain assessment in these RCTs, a between-group difference in pain with 95% confidence intervals within or across these RCTs was not estimated. 

Cost: dressing changes

Zuccarelli 1992 reported the mean number of dressing changes over the 12 weeks of treatment as being 26.9 in the hydrocolloid group compared with 19.5 in the hydrocellular foam dressing group. The trialists did not report variance data, but did report that the between-group difference was not statistically significant (P value 0.14). 

Bowszyc 1995 reported the UK Drug Tariff price per dressing (at October 1993) as GBP 2.08 for a 10 cm x 10 cm piece of the hydrocolloid dressing compared with GBP 0.92 for a 10 cm x 10 cm piece of the polyurethane foam dressing. The reported mean number of dressing changes per week in the first month was 1.5 in the hydrocolloid group compared with 1.6 in the foam group. The trialists reported no variance data nor a statistically significant between-group difference (P value 0.49). 

The mean (SD) number of dressing changes per week in the RCT by Vanscheidt 2004 was 11.4 (6.5) in the group receiving the hydrocolloid dressing compared with 10.1 (6.3) in the group receiving the hydrocellular foam dressing. The trialists reported that there was no statistically significant between-group difference in this dressing performance outcome, however, the number of participants in each treatment group at follow up was not reported. 

We could not estimate between-group differences in the number of dressing changes with 95% confidence intervals for foam dressings compared with hydrocolloid dressings from these RCTs. 

Cost: wear time

Thomas 1997 reported that the mean time that the original dressing was in place prior to the first change was 2.7 days in the group receiving the hydrocolloid dressing compared with 2.8 days in the group receiving the polyurethane foam dressing. The trialists reported no variance data, nor the P value for between-group difference.

Vanscheidt 2004 reported that the mean (SD) wear time was 5.6 (1.3) days in the hydrocolloid group compared with 5.6 (1.2) days in the hydrocellular foam group. The trialists reported that there was no statistically significant between-group difference in this outcome, however, they did not report the number of participants in each treatment group at follow up.

Dressing performance: exudate management

Thomas 1997 reported that 27/50 (54%) of participants in the hydrocolloid group had dressings removed at the first dressing change due to leakage compared with 7/50 (14%) in the polyurethane foam group. The trialists reported that the between-group difference was statistically significant (P value < 0.0001).

In the RCT by Vanscheidt 2004, the exudate-handling property of the dressing was reported in terms of the number of dressing changes where no exudate, minimal exudate (i.e. less than 25% of dressing saturated), moderate exudate (25% to 75% of dressing saturated), or considerable exudate (more than 75% of dressing saturated) was observed. The proportion of dressing changes in each category appeared similar between groups (approximately 8%, 35%, 38% and 19% respectively), however, the trialists did not report a P value for the between-group differences. 

Ease of dressing removal/adherence to the wound bed

The RCT by Bowszyc 1995, assessed nurse-rated ease of dressing removal using an 11-point scale (0 = easy to remove, 11 = difficult to remove). The mean (SD) score in the hydrocolloid group was 1.42 (0.54) compared with 1.15 (0.42) in the polyurethane foam group. The trialists reported a P value of 0.016 for the between-group difference.

Thomas 1997 reported that in both treatment groups, dressing removal was rated by nurses as 'easy' in the majority of cases at the first dressing change, however, no data by group were presented.

In the three-arm RCT by Charles 2002, the foam dressing was reported to be significantly easier to remove compared with the two hydrocolloid dressings at six weeks and at the last dressing change (P value 0.021 and P value 0.037 respectively for the two time points), however, it was unclear how these P values related to the between-group comparisons, given that the trialists would have been considering three comparisons at each time point. No between-group difference with 95% confidence intervals could be estimated for this RCT.

Vanscheidt 2004 assessed participant-rated ease of dressing removal and non-traumatic dressing removal on a five-point scale (1 = excellent, 2 = very good, 3 = good, 4 = fair, 5 = poor) at the final evaluation. The proportions of participants reporting dressing changes in each of the five categories for each outcome by treatment group were presented graphically, however, the denominator (number of participants in each treatment group) was not presented. The trialists reported a between-group difference of P value 0.19 for ease of removal and P value 0.07 for non-traumatic dressing removal. No between-group differences with 95% confidence intervals could be estimated from this RCT.

Hydrocolloid dressings compared with foam dressings: summary of results

Pooled evidence from five RCTs indicated no statistically significant difference between hydrocolloid dressings and foam dressings in the proportion of ulcers completely healed from 12 to 16 weeks (Zuccarelli 1992; Bowszyc 1995; Thomas 1997; Charles 2002; Vanscheidt 2004). One of these RCTs was considered to be at overall high risk of bias (Charles 2002), whilst the others were judged as unclear.

Evidence from one RCT indicated no statistically significant between-group difference in the number of participants experiencing dressing-related adverse events. Insufficient data were provided to estimate measures of treatment effect for other outcomes, however, it is possible that the foam dressing was better than hydrocolloid for exudate handling and ease of removal.

Knitted viscose dressings compared with foam dressings

We identified one RCT that compared a knitted viscose dressing with a hydrocellular polyurethane foam dressing (Callam 1992). This RCT had a factorial design in which participants were randomised to one of two compression bandage systems as well as to one of two dressings. One of the compression systems consisted of orthopaedic padding, a high-compression elastic bandage and a graduated compression tubular bandage; the other comprised orthopaedic padding, a short-stretch crepe bandage, and a short-stretch cohesive bandage. Sixty-six participants were randomised to receive the knitted viscose dressing and 66 to receive the foam dressing. There was no statistically significant interaction between dressings and bandages (P value 0.87). The length of treatment was 12 weeks, or until the ulcer healed, whichever occurred sooner. 

Primary outcomes

Time to healing

Callam 1992 reported no significant difference between groups from a Cox regression model adjusted for baseline ulcer size (P value 0.08 but no hazard ratio estimate provided).

Proportion of ulcers completely healed

At the end of 12 weeks of treatment Callam 1992 reported that 23/66 (35%) of ulcers had healed in the knitted viscose group compared with 31/66 (47%) in the hydrocellular foam group. The between-group difference was not statistically significant (RR 1.35, 95% CI 0.89 to 2.05) (Analysis 5.1). The trialists considered participants who withdrew from treatment as failures of treatment rather than lost to follow up. This RCT was at overall high risk of bias. 

Change in ulcer size

Callam 1992 reported a categorical analysis for percentage change in ulcer area from baseline to 12 weeks or participant withdrawal. Seven categories were used: more than 100% increase, 50% to 100% increase, 0% to 50% increase, 0% to 50% decrease, 50% to 100% decrease, healed and not known; data were presented in a figure. Initial or final ulcer tracings were not available for three participants, and these were excluded from the analysis. A P value of 0.051 was reported by the trialists for the overall between-group difference in ulcer area reduction.

Secondary outcomes
Adverse events

Callam 1992 reported that there were no cases of adverse reactions in the knitted viscose dressing group and that 2/66 (2%) of the hydrocellular foam group experienced local skin reactions. The between-group difference was not statistically significant (RR 5.00, 95% CI 0.24 to 102.19) (Analysis 5.2).

Pain

Callam 1992 assessed the number of participants experiencing pain at 0%, 1% to 25%, 26% to 50%, 51% to 75%, 76% to 99%, and 100% of clinic visits. The trialists reported P value 0.01 in favour of the foam dressing for the between-group difference in patients experiencing pain at all (100%) clinic visits.

Knitted viscose dressings compared with foam dressings: summary of results

Evidence from one RCT suggested no statistically significant difference between knitted viscose dressings and foam dressings in the proportion of ulcers completely healed at 12 weeks (Callam 1992). This RCT was considered to be at overall high risk of bias. Data from the same RCT indicated no statistically significant between-group difference in the number of participants who experienced adverse events during treatment. Insufficient data were available to estimate measures of treatment effect for other outcomes, however, it is possible that the foam dressing is associated with less pain than the knitted viscose dressing.

Protease-modulating matrix dressing compared with foam dressing

We identified one three-armed RCT that compared a protease-modulating dressing, a paraffin gauze dressing and a foam dressing (Andriessen 2009). The comparison between the paraffin gauze and foam dressings has been described earlier.

Primary outcomes
Change in ulcer size

Andriessen 2009 reported that the mean percentage change in ulcer area (range) at four weeks was -31.8% (-28 to -34%) in the protease-modulating matrix group compared with -26.4% (-17.3 to -32%) in the polyurethane foam group. The trialists did not report a P value for the between-group differences. No other variance data were reported. A mean between-group difference with 95% CI could not be estimated for this outcome.

Secondary outcomes
Adverse events

Andriessen 2009 recorded the severity and timing of any adverse event and reported that no adverse events were observed during the RCT.

Pain

Using data generated from a 10-point VAS (with lower scores representing less pain), Andriessen 2009 reported that participants experienced little or no pain (classified from a mean VAS score of 1 to 2) in both groups. 

Dressing performance: adherence to the wound bed

Andriessen 2009 reported that the paraffin gauze dressing stuck to the wound bed in 72% of the dressing changes (total number of dressing changes not provided), but there was no report of this outcome for the foam or protease-modulating dressing groups.

Protease-modulating matrix dressings compared with foam dressings: summary of results

A single RCT reported this comparison (Andriessen 2009); available data were very limited and therefore inconclusive.

Summary of Findings tables

We have included a Summary of Findings table for the following treatment comparisons; these provide a concise overview and synthesis of the volume and quality of available evidence.

There is no Summary of Findings table for foam compared with protease-modulating matrix dressings because only limited data were reported in the single RCT evaluating this comparison (Andriessen 2009).

The Summary of Findings tables indicate that, where evidence is available, it is generally of low quality. The exception to this was for the outcome of complete healing (at 12 to 16 weeks) for the comparison of foam and hydrocolloid dressings, where the evidence was of moderate quality. Overall, the Summary of Findings tables indicated that there is no evidence of a benefit of using foam dressings compared with alternative dressings for treating venous leg ulcers.

Discussion

The purpose of this review was to determine the effects of foam dressings compared with alternatives on the healing of venous leg ulcers. In addition, we considered the effects of these dressing on: adverse events, health-related quality of life, costs, pain, and dressing performance (management of wound exudate and ease of removal).

Summary of main results

Twelve RCTs were included in this review. Three compared two types of foam dressings (Weiss 1996; Andersen 2002; Franks 2007), whilst the others involved comparison between foam and other types of dressings. The comparator dressings were: paraffin gauze (Banerjee 1990; Andriessen 2009); protease-modulating matrix (Andriessen 2009); hydrocapillary (Norkus 2005); hydrocolloid (Zuccarelli 1992; Bowszyc 1995; Thomas 1997; Charles 2002; Vanscheidt 2004); and knitted viscose (Callam 1992).

Primary outcomes

No statistically significant differences were detected between treatment groups for any healing outcome for comparisons of different variants of foam dressings, nor for foam compared with other types of dressings (paraffin gauze, hydrocapillary, hydrocolloid, knitted viscose and protease-modulating matrix). The length of follow up varied across RCTs and ranged between four weeks and one year. Meta-analysis was feasible for one comparison (foam compared with hydrocolloid) where five RCTs were pooled for the outcome of complete healing at 12 to 16 weeks: RR 1.00 (95% CI 0.81 to 1.22).

Secondary outcomes

Secondary outcomes included adverse events, health-related quality of life, costs, pain and dressing performance; outcome definition varied across RCTs. Data were generally sparse for the outcomes of health-related quality of life and costs/resource use.

Where the review authors were able to estimate measures of treatment effect from the available data, no statistically significant between-group differences in the proportion of participants experiencing adverse events were detected when hydrocellular foam dressings were compared with polyurethane foam dressings (Franks 2007), or when foam dressings were compared with hydrocapillary (Norkus 2005), hydrocolloid (Vanscheidt 2004), or knitted viscose dressings (Callam 1992). Regarding dressing performance, data from one RCT suggested that the polyurethane foam dressing may be superior to hydrocellular foam for handling exudate (Andersen 2002), and other data indicated that foam dressings could be better than hydrocolloid for the same outcome plus ease of removal (Bowszyc 1995; Thomas 1997). One RCT described fewer reports of pain for the foam dressing when compared with knitted viscose dressings (Callam 1992), whilst another found no difference in pain scores between groups receiving hydrocellular foam and polyurethane foam dressings (Franks 2007). Otherwise, RCTs either reported no statistically significant differences between groups for these outcomes, or, more commonly, presented only limited information. The secondary outcome data should generally be viewed with caution because of the subjective (and non-blind) nature of the assessments.

Overall completeness and applicability of evidence

Participant and intervention characteristics

The majority of participants were ambulatory and had venous leg ulceration confirmed with ABPI assessment; these characteristics are likely to approximate to patients seen in clinical practice. Several RCTs imposed limits to the baseline wound size, sometimes with the idea of recruiting participants with wound sizes which would not exceed the study dressing dimensions (Weiss 1996; Thomas 1997; Andersen 2002; Charles 2002; Vanscheidt 2004). Also, most RCTs listed clinical infection of the ulcer as an exclusion criterion. This may limit applicability to clinical practice, where people with a wide range of wound sizes and/or infected ulcers are likely to be encountered. A further factor which could limit external validity is that nine of the 12 RCTs included were published ten, or more, years ago. If there are differences in earlier versions of foam dressings relative to their more recent counterparts, differential responses to treatment may be observed in clinical practice relative to this body of evidence.

With one exception (Banerjee 1990), all of the included RCTs reported the use of compression therapy as part of the intervention, so we were unable to undertake our planned subgroup analysis for the concurrent presence versus absence of compression. The types of compression therapy differed across the RCTs and included both elastic and short-stretch bandage systems with varying components, and compression stockings.

Primary outcomes

Time to healing was assessed in seven of the 12 included RCTs, however, the analysis method was unclear in one RCT and no data by group were reported (Norkus 2005). Five RCTs evaluated this outcome as a mean time to healing (Bowszyc 1995; Weiss 1996; Andersen 2002; Charles 2002; Vanscheidt 2004). This analysis approach would only account for those participants whose ulcers healed. Participants whose ulcers did not heal during the RCT (censored data) would not have been accounted for by this analysis method which could have resulted in a biased effect estimate (Deeks 2011). Only one RCT, comparing a hydrocellular foam dressing with a polyurethane foam dressing, reported survival analysis as hazard ratios for time to healing, reporting that there was no statistically significant between-group difference over 24 weeks (Franks 2007). The limited way in which this outcome was analysed and reported across the other RCTs restricts any inference regarding the efficacy of foam dressings in terms of time to healing across this body of evidence.

With one exception (Andriessen 2009), all included RCTs reported the proportion of ulcers healed and we were able to estimate between-group differences from these RCTs for this outcome. For three comparisons, estimates were based on a single RCT: foam versus paraffin gauze (Banerjee 1990); foam versus hydrocapillary dressing (Norkus 2005); and foam versus knitted viscose dressing (Callam 1992).

Due to limited reporting in four RCTs that evaluated change in ulcer size (Callam 1992; Weiss 1996; Andersen 2002; Andriessen 2009), specifically in terms of variance estimates, no estimation of between-group differences could be undertaken. None of these RCTs adjusted for baseline ulcer size.

Secondary outcomes

All secondary outcomes varied greatly across the included RCTs in terms of outcome definition, methods of assessment and reporting quality. Lack of available data meant that the review authors were unable to estimate between-group differences in many instances.

In terms of adverse events, only four RCTs provided sufficient data to enable estimation of between-group differences (Callam 1992; Vanscheidt 2004; Norkus 2005; Franks 2007). Cost and resource use data (e.g. mean number of dressing changes) were infrequently reported and where mean values were provided, often lacked variance data, or P values for tests of between-group differences, or both. The method and timing of assessments of pain was varied, and no estimates for between-group differences could be undertaken by the review authors. Outcomes relating to dressing performance were assessed subjectively, using non-validated methods. One RCT reported that dressings were weighed to measure the amount of exudate; whilst this is potentially a more objective method of assessment, no results were presented (Norkus 2005). A quality of life assessment was reported by only one RCT (Norkus 2005), with only limited data provided.

Quality of the evidence

Six of the 12 included RCTs were considered to be at overall high risk of bias (Banerjee 1990; Callam 1992; Weiss 1996; Andersen 2002; Charles 2002; Franks 2007), and the remaining six were classified as having unclear risk of bias overall (Zuccarelli 1992; Bowszyc 1995; Thomas 1997; Vanscheidt 2004; Norkus 2005; Andriessen 2009). Of those at high risk of bias, three compared two types of foam dressings (Weiss 1996; Andersen 2002; Franks 2007), one compared a paraffin-impregnated gauze dressing with foam (Banerjee 1990), one compared hydrocolloid dressing with foam (Charles 2002), and one compared knitted viscose dressing with foam dressing (Callam 1992). In three of these, the outcome assessment was not blinded (Weiss 1996; Andersen 2002; Franks 2007), and in four not all participants who were randomised were accounted for in the analysis (Banerjee 1990; Callam 1992; Andersen 2002; Charles 2002). Missing outcome data, due to attrition (drop-out) during the trial or exclusion of participants from the analysis can bias the effect estimate, and lack of blinding of participants or healthcare providers could bias the results by affecting the actual outcomes of the participants in the trial (Higgins 2011a). Two RCTs were described as pilot studies, and had very small sample sizes (Weiss 1996; Andriessen 2009). One RCT presented a unit of analysis issue as, whilst the participants were the unit of randomisation, the unit of analysis was legs, with some participants reported as having bilateral leg ulcers (Bowszyc 1995). An important principle of any RCT is that the analysis must take into account the level at which randomisation occurred and the number of observations in the analysis should match the number of ‘units’ that were randomised (Deeks 2011).

All of the RCTs identified for inclusion in this review were published prior to the current CONSORT (Consolidated Standards of Reporting Trials) guidelines for the reporting of RCTs (Schulz 2010). Key aspects of best practice in RCT design to minimise bias include a robust randomisation method, concealment of treatment group allocation, and, where possible, blinding of participants and trial personnel, and blinded outcome assessment; all of which should be clearly stated in the RCT report. The majority of the included RCTs in this review did not report the method of the random sequence generation or an adequate method of allocation concealment.

The Summary of Findings tables indicate that the current evidence base for the effects of foam dressings compared with alternatives on the healing of venous leg ulcers is mainly of low quality. The quality of available evidence for the outcome of complete healing at 12 to 16 weeks for the comparison of foam and hydrocolloid dressings was moderate. A Summary of Findings table was not generated for the comparison between foam and protease-modulating matrix dressings because only limited data were reported (Andriessen 2009). This highlights a potential gap in the evidence base as there is currently much interest in the role of proteases in chronic wound management (Ovington 2007; Snyder 2012).

Potential biases in the review process

In addition to the electronic searches of bibliographic databases, the search for evidence for this review included handsearching, contact with trialists and manufacturers, and the searching of ongoing trials registers. Although this search strategy was comprehensive, the possibility of publication bias cannot be discounted. Nonetheless, given the high or unclear risk of bias of the RCTs identified for inclusion, coupled with the absence of any significant treatment effects on ulcer healing, it is considered unlikely that any additional unpublished data would contribute significantly to the overall findings of this review.

Agreements and disagreements with other studies or reviews

The evidence base to guide dressing choice suggests that there is no evidence to support foam dressings as being better or worse than other dressing treatments for the healing of venous leg ulcers. This observation is in agreement with the systematic review by Palfreyman 2007, who concluded that there were insufficient data available to draw strong conclusions about any one dressing type being more effective in healing venous leg ulcers; the review did not comment on foam dressings specifically. Only eight of the 12 RCTs of foam dressings included in this review were included in the review by Palfreyman 2007.

Authors' conclusions

Implications for practice

At present there is no evidence to suggest that foam dressings are better or worse than any other primary wound contact dressing for the healing of venous leg ulcers when applied beneath compression devices. However, the current evidence base is mainly of low quality. The lack of good quality evidence limits specific recommendations regarding the use of any of the dressing types reviewed here for the healing of venous leg ulcers. Further, good quality evidence is required from well designed RCTs prior to it being possible to draw definitive conclusions regarding the efficacy of foam dressings in the management of venous leg ulcers.

Implications for research

Most of the RCTs included in this review have methodological and reporting problems.  The majority were published more than 10 years ago, and might not reflect current clinical practice. Those planning future RCTs should consider whether participants are likely to represent patients seen in clinical practice in terms of ulcer size, ulcer duration and the presence of ulcer infection. Ulcer infection was an exclusion criterion in a large number of the included RCTs whereas practitioners are likely to encounter many patients with ulcer infection in clinical practice. Future RCTs should undertake the following in order to minimise bias: robust randomisation and concealment of allocation methods; blinded outcome assessment; analysis by intention-to-treat; and appropriate estimation of time to healing using survival analysis. In addition, future RCTs should be adequately powered to detect treatment effects. Methodological details should be clearly reported in line with the CONSORT (Consolidated Standards of Reporting Trials) guidelines for the reporting of RCTs (Schulz 2010).

Further research that fully investigates the safety and tolerability of wound dressings for venous leg ulcers is required, comprising clear evaluation and reporting of dressing-related adverse events. Quality of life assessment should be undertaken using a valid and reliable assessment instrument and results reported in full. As dressing choice for the management of venous leg ulcers may be guided by cost, future RCTs should present clear and meaningful cost-effectiveness information.

Acknowledgements

We are very grateful to the following peer referees who provided valuable feedback on the draft of the review: Ruth Foxlee, Richard Kirubakaran, Jane Nadel, Andrea Nelson, Rachel Richardson, and Nikki Stubbs. We also thank Nikki Stubbs for advice regarding the comparability of dressings. Thanks are due to Daisy Gregory, Kirsty Benn-Harris, Belen Corbacho and Jeppe Schroll for their help with translation, and also to Elizabeth Royle for assistance with copy editing. We should like to express appreciation for the support we have received from the staff of the Cochrane Wounds Group - to Ruth Foxlee for advising on the search strategy and running the database searches and to Sally Bell-Syer for helpful advice and assistance with preparing the draft review.

Finally, we would like to thank Smith & Nephew for allowing us to use information contained in the Lothian and Forth Valley Leg Ulcer Healing Trial final report and statistical report (unpublished material) associated with Callam 1992.

Data and analyses

Download statistical data

Comparison 1. Hydrocellular foam compared with polyurethane foam
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Proportion of ulcers completely healed3 Risk Ratio (M-H, Fixed, 95% CI)Subtotals only
1.1 Ulcers healed at 8 weeks1118Risk Ratio (M-H, Fixed, 95% CI)1.03 [0.60, 1.78]
1.2 Ulcers healed at 16 weeks118Risk Ratio (M-H, Fixed, 95% CI)1.6 [0.75, 3.42]
1.3 Ulcers healed at 24 weeks1156Risk Ratio (M-H, Fixed, 95% CI)1.08 [0.85, 1.37]
2 Participants experiencing adverse events1156Risk Ratio (M-H, Fixed, 95% CI)1.13 [0.69, 1.85]
Analysis 1.1.

Comparison 1 Hydrocellular foam compared with polyurethane foam, Outcome 1 Proportion of ulcers completely healed.

Analysis 1.2.

Comparison 1 Hydrocellular foam compared with polyurethane foam, Outcome 2 Participants experiencing adverse events.

Comparison 2. Paraffin gauze compared with foam
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Proportion of ulcers healed at 17 weeks171Risk Ratio (M-H, Fixed, 95% CI)1.34 [0.61, 2.92]
Analysis 2.1.

Comparison 2 Paraffin gauze compared with foam, Outcome 1 Proportion of ulcers healed at 17 weeks.

Comparison 3. Hydrocapillary compared with foam
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Proportion of ulcers healed at 12 months197Risk Ratio (M-H, Fixed, 95% CI)0.78 [0.50, 1.21]
2 Participants experiencing adverse events197Risk Ratio (M-H, Fixed, 95% CI)1.40 [0.62, 3.18]
Analysis 3.1.

Comparison 3 Hydrocapillary compared with foam, Outcome 1 Proportion of ulcers healed at 12 months.

Analysis 3.2.

Comparison 3 Hydrocapillary compared with foam, Outcome 2 Participants experiencing adverse events.

Comparison 4. Hydrocolloid compared with foam
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Proportion of ulcers completely healed at 12 to 16 weeks5 Risk Ratio (M-H, Fixed, 95% CI)Subtotals only
1.1 Meta-analysis including Comfeel study arm from Charles 20025387Risk Ratio (M-H, Fixed, 95% CI)0.99 [0.80, 1.22]
1.2 Meta-analysis including Granuflex study arm from Charles 20025389Risk Ratio (M-H, Fixed, 95% CI)1.00 [0.81, 1.24]
1.3 Meta-analysis including Comfeel and Granuflex study arms combined from Charles 20025418Risk Ratio (M-H, Fixed, 95% CI)1.00 [0.81, 1.22]
2 Participants experiencing dressing-related adverse events1107Risk Ratio (M-H, Fixed, 95% CI)1.22 [0.64, 2.31]
Analysis 4.1.

Comparison 4 Hydrocolloid compared with foam, Outcome 1 Proportion of ulcers completely healed at 12 to 16 weeks.

Analysis 4.2.

Comparison 4 Hydrocolloid compared with foam, Outcome 2 Participants experiencing dressing-related adverse events.

Comparison 5. Knitted viscose compared with foam
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Proportion of ulcers healed at 12 weeks1132Risk Ratio (M-H, Fixed, 95% CI)1.35 [0.89, 2.05]
2 Participants experiencing adverse events1132Risk Ratio (M-H, Fixed, 95% CI)5.0 [0.24, 102.19]
Analysis 5.1.

Comparison 5 Knitted viscose compared with foam, Outcome 1 Proportion of ulcers healed at 12 weeks.

Analysis 5.2.

Comparison 5 Knitted viscose compared with foam, Outcome 2 Participants experiencing adverse events.

Appendices

Appendix 1. Glossary

Aetiology: the underlying cause of diseases and disorders (Cochrane Wounds Group Glossary).
Autolytic: the destruction of tissues or cells of an organism by the action of substances, such as enzymes, that are produced within the organism (The Free Medical Dictionary).
Debride/debridement: the removal of foreign material and dead or damaged tissue from a wound (Cochrane Wounds Group Glossary).
Exudate: fluid that leaks out of a wound (Cochrane Wounds Group Glossary).
Fibrinolytic therapy: the use of special drugs to break up blood clots (The Free Medical Dictionary).
Haemodynamic(s): the study of the forces involved in the circulation of blood (The Free Medical Dictionary).
Lipodermatosclerosis: area of pigmentation and hardened skin caused by leakage of red blood cells into the skin. Seen in people with chronic venous insufficiency, affecting the skin just above the ankle (Cochrane Wounds Group Glossary).
Macerate/maceration: the softening and breaking down of skin resulting from prolonged exposure to moisture (The Free Medical Dictionary).
Photoplethysmography: an optically-obtained plethysmograph (an instrument for measuring changes in volume), of a volumetric measurement of an organ (The Free Medical Dictionary).

Proteolysis: the breakdown of proteins into simpler, soluble substances such as peptides and amino acids, as occurs during digestion (The Free Medical Dictionary).
Slough: a layer or mass of dead tissue separated from surrounding living tissue, as in a wound, a sore, or an inflammation (The Free Medical Dictionary).
Vasoactive: causing constriction or dilation of blood vessels (The Free Medical Dictionary).

Appendix 2. British National Formulary 2012 categories of dressings

Basic wound contact dressings

Low-adherence dressings

Low adherence dressings are usually cotton pads that are placed directly in contact with the wound. These dressings can be used as interface layers under secondary absorbent dressings and are suitable for clean, granulating, lightly exuding wounds without necrosis; they protect the wound bed from direct contact with secondary dressings. Care must be taken to avoid granulation tissue growing into the weave of these dressings. Tulle dressings are manufactured from cotton or viscose fibres which are impregnated with white or yellow soft paraffin to prevent the fibres from sticking, but this is only partly successful and it may be necessary to change the dressings frequently. The paraffin reduces absorbency of the dressing. Knitted viscose is an alternative primary dressing to tulle dressings for exuding wounds; it can be used as the initial layer of multi-layer compression bandaging in the treatment of venous leg ulcers (BNF 2013). Examples include Atrauman® (Hartmann) and Tricotex® (Smith and Nephew).

Absorbent dressings

Dressings with an absorbent cellulose or polymer wadding layer are suitable for use on moderately to heavily exuding wounds. These may be applied directly to the wound and may be used as secondary absorbent layers in the management of heavily exuding wounds (BNF 2013). Examples include Exu-Dry® (Smith and Nephew) and KerraMax® (Ark Therapeutics).

Advanced wound dressings

Hydrogel dressings

Hydrogel dressings consist of cross-linked insoluable polymers (i.e. starch or carboxymethylcellulose) and up to 96% water. They are supplied as either flat sheets, or an amorphous hydrogel, or as beads. These dressings are generally used to donate liquid to dry sloughy wounds and facilitate autolytic debridement of necrotic tissue; some also have the ability to absorb very small amounts of exudate. When used, a secondary, non-absorbent dressing is also required (BNF 2013). Examples include ActiFormCool® (Activa) and Intrasite Conformable® (Smith and Nephew).

Vapour-permeable films and dressings

Vapour-permeable films and dressings come in the form of a transparent film, usually with an adhesive base that is applied to the wound. Vapour-permeable films and membranes allow the passage of water vapour and oxygen, but are impermeable to water and micro-organisms, and are suitable for lightly exuding wounds. Vapour-permeable films and membranes are unsuitable for infected, large, heavily exuding wounds. Most commonly, they are used as a secondary dressing over alginates or hydrogels (BNF 2013). Examples include OpSite® (Smith and Nephew) and Tegaderm® (3M).

Soft polymer dressings

Dressings with soft polymer, often a soft silicone polymer, in a non-adherent or gently-adherent layer are suitable for use on lightly to moderately exuding wounds. For moderately to heavily exuding wounds, an absorbent secondary dressing can be added, or a soft polymer dressing with an absorbent pad can be used (BNF 2013). Examples include Mepilex® (Mölnlycke) and Urgotul® (Urgo).

Hydrocolloid dressings

Hydrocolloid dressings are occlusive dressings usually composed of a hydrocolloid matrix bonded onto a vapour-permeable film or foam backing. When in contact with the wound and with exudate, these dressings form a gel to facilitate rehydration in lightly to moderately exuding wounds (BNF 2013). Examples include DuoDERM® Extra Thin (ConvaTec) and Tegaderm® Hydrocolloid (3M).

Foam dressings

Foam dressings contain hydrophilic foam and are suitable for all types of exuding wounds. They vary in their ability to absorb exudates; some are suitable only for lightly to moderately exuding wounds, others have a greater fluid-handling capacity. They can be used in combination with other primary wound contact dressings, but are usually placed over the ulcer prior to the application of compression bandages or hosiery, with the intention of promoting healing and preventing the bandages from sticking to the wound. Saturated foam dressings can cause maceration of healthy skin if left in contact with the wound. If used under compression bandaging or compression garments, the fluid handling capacity of foam dressings may be reduced (BNF 2013). Examples include Allevyn® Non-Adhesive (Smith and Nephew) and Biatain® Non-Adhesive (Coloplast).

Alginate dressings

Alginate dressings are non-occlusive dressings, made from calcium alginate, or calcium sodium alginate (derived from brown seaweed). The alginate forms a gel when in contact with exudate at the wound surface. This gel can be lifted off during dressing removal or rinsed away with sterile saline. Alginate dressings are highly absorbent and suitable for use on exuding wounds, and for the promotion of autolytic debridement of debris in very moist wounds. Alginate sheets are suitable for use as a wound contact dressing for moderately to heavily exuding wounds and can be layered into deep wounds. If the dressing does not have an adhesive border or integral adhesive plastic film backing, a secondary dressing will be required. Examples include Curasorb® (Covidien) and Sorbsan® (Aspen Medical).

Capillary-action dressings

Capillary-action dressings consist of an absorbent core of hydrophilic fibres held between two low-adherent wound-contact layers to ensure no fibres are shed on to the wound surface. Wound exudate is taken up by the dressing and retained within the highly absorbent central layer. Capillary-action dressings are suitable for use on all types of exuding wounds, but particularly on sloughy wounds where removal of fluid from the wound aids debridement (BNF 2013). Examples include Advadraw® (Advancis) and Vacutex® (Protex).

Odour-absorbant dressings

Dressings containing activated charcoal are used to absorb odour from wounds. Many odour absorbent dressings are intended for use in combination with other dressings and are often used in conjunction with a secondary dressing to improve absorbency (BNF 2013). Examples include CarboFLEX® (ConvaTec) and CliniSorb® Odour Control Dressings (CliniMed).

Antimicrobial dressings

Honey

Medical grade honey has antimicrobial and anti-inflammatory properties and can be used for acute or chronic wounds. It is available in sheet-dressing form or as a honey-base topical application applied directly to the wound and covered with a primary low-adherence wound dressing (BNF 2013). Examples include Medihoney® (Medihoney) and Mesitran® (Aspen Medical).

Iodine

Both cadexomer–iodine and povidone–iodine release free iodine when exposed to wound exudate. The free iodine acts as an antiseptic on the wound surface, the cadexomer absorbs wound exudate and encourages de-sloughing. Two-component hydrogel dressings containing glucose oxidase and iodide ions generate a low level of free iodine in the presence of moisture and oxygen. A povidone–iodine fabric dressing is a knitted viscose dressing into which povidone–iodine has been incorporated in a hydrophilic polyethylene glycol basis. The iodine has a wide spectrum of antimicrobial activity but it is rapidly deactivated by wound exudate (BNF 2013). Examples include Iodoflex® (Smith and Nephew) and Iodosorb® (Smith and Nephew).

Silver

Antimicrobial dressings containing silver are available as: low-adherent dressings, with knitted fabric of activated charcoal, soft polymer dressings, hydrocolloid dressings, foam dressings and alginate dressings. Silver ions exert an antimicrobial effect in the presence of wound exudate. Antimicrobial dressings containing silver should be used only when infection is suspected on the basis of clinical signs or symptoms (BNF 2013). Examples include Acticoat® (Smith and Nephew), Aquacel® Ag (ConvaTec) and Biatain® Ag (Coloplast).

Other antimicrobial dressings

A number of dressings that are impregnated with other antimicrobial agents such as chlorhexidine and polyhexanide are also available (BNF 2013). Examples include chlorhexidine gauze dressing, BP 1993 and Suprasorb® X + PHMB (Activa).

Specialised dressings

Protease-modulating matrix dressings

Protease-modulating matrix dressings alter the activity of proteolytic enzymes in chronic wounds (BNF 2013). Examples include Promogran® (Systagenix) and UrgoStart® (Urgo).

Appendix 3. Search strategies for Ovid Medline, Ovid Embase and EBSCO CINAHL

Ovid Medline

1 exp Occlusive Dressings/ (3300)
2 foam*1.tw. (12260)
3 (ActivHeal or Allevyn or Avazorb or Biatain or Copa or LyoFoam or PermaFoam or PolyMem or Suprasorb or Tegaderm or Tielle or Transobent or Trufoam or UrgoCell).tw. (554)
4 or/1-3 (15882)
5 exp Leg Ulcer/ (15502)
6 (varicose ulcer* or venous ulcer* or leg ulcer* or stasis ulcer* or crural ulcer* or ulcus cruris or ulcer cruris).tw. (6261)
7 or/5-6 (16680)
8 4 and 7 (421)
9 randomized controlled trial.pt. (316214)
10 controlled clinical trial.pt. (83227)
11 randomized.ab. (221732)
12 placebo.ab. (127298)
13 clinical trials as topic.sh. (157023)
14 randomly.ab. (160555)
15 trial.ti. (95248)
16 or/9-15 (734544)
17 (animals not (humans and animals)).sh. (3550250)
18 16 not 17 (677587)
19 8 and 18 (87)

Ovid Embase

1 exp occlusive dressing/ (397)
2 exp foam dressing/ (169)
3 foam*1.tw. (13113)
4 (ActivHeal or Allevyn or Avazorb or Biatain or Copa or LyoFoam or PermaFoam or PolyMem or Suprasorb or Tegaderm or Tielle or Transobent or Trufoam or UrgoCell).tw. (699)
5 or/1-4 (14148)
6 exp leg ulcer/ (5933)
7 (varicose ulcer* or venous ulcer* or leg ulcer* or stasis ulcer* or crural ulcer* or ulcus cruris or ulcer cruris).tw. (5351)
8 or/6-7 (7800)
9 5 and 8 (210)
10 Randomized controlled trials/ (21460)
11 Single-Blind Method/ (15103)
12 Double-Blind Method/ (84307)
13 Crossover Procedure/ (30966)
14 (random$ or factorial$ or crossover$ or cross over$ or cross-over$ or placebo$ or assign$ or allocat$ or volunteer$).ti,ab. (911523)
15 (doubl$ adj blind$).ti,ab. (87873)
16 (singl$ adj blind$).ti,ab. (9324)
17 or/10-16 (943260)
18 animal/ (712703)
19 human/ (8384785)
20 18 not 19 (475542)
21 17 not 20 (911699)
22 9 and 21 (44)

EBSCO CINAHL

S8 S4 and S7
S7 S5 or S6
S6 TI ( varicose ulcer* or venous ulcer* or leg ulcer* or stasis ulcer* or crural or cruris ) OR AB ( aricose ulcer* or venous ulcer* or leg ulcer* or stasis ulcer* or crural or cruris )
S5 (MH "Leg Ulcer+")
S4 S1 or S2 or S3
S3 TI ( activheal or allevyn or avazorb or biatain or copa or lyofoam or permafoam or polymem or suprasorb or tegaderm or tielle or transobent or trufoam or urgocell ) OR AB ( activheal or allevyn or avazorb or biatain or copa or lyofoam or permafoam or polymem or suprasorb or tegaderm or tielle or transobent or trufoam or urgocell )
S2 TI foam* OR AB foam*
S1 (MH "Occlusive Dressings")

Appendix 4. Dressing manufacturers the review authors contacted regarding ongoing or recently completed trials of alginate dressings

3M
Advancis
Ark Therapeutics
Aspen Medical
Braun
BSN Medical
Coloplast
Covidien
Hartmann
MedLogic
Mölnlycke
Smith & Nephew Healthcare
Systagenix
Urgo

Appendix 5. 'Risk of bias' criteria

1. Was the allocation sequence randomly generated?

Low risk of bias: the investigators describe a random component in the sequence generation process such as: referring to a random number table; using a computer random number generator; coin tossing; shuffling cards or envelopes; throwing dice; drawing of lots.

High risk of bias: the investigators describe a non-random component in the sequence generation process. Usually, the description would involve some systematic, non-random approach, for example: sequence generated by odd or even date of birth; sequence generated by some rule based on date (or day) of admission; sequence generated by some rule based on hospital or clinic record number.

Unclear risk of bias: insufficient information about the sequence generation process to permit judgement of low or high risk of bias.

2. Was the treatment allocation adequately concealed?

Low risk of bias: participants and investigators enrolling participants could not foresee assignment because one of the following, or an equivalent method, was used to conceal allocation: central allocation (including telephone, web-based and pharmacy-controlled randomisation); sequentially-numbered drug containers of identical appearance; sequentially-numbered, opaque, sealed envelopes.

High risk of bias: participants or investigators enrolling participants could possibly foresee assignments and thus introduce selection bias, because using allocation system based on: using an open random allocation schedule (e.g. a list of random numbers); assignment envelopes were used without appropriate safeguards (e.g. when envelopes were unsealed or non-opaque or not sequentially numbered); alternation or rotation; date of birth; case record number; any other explicitly unconcealed procedure.

Unclear risk of bias: insufficient information to permit judgement of low or high risk of bias. This is usually the case if the method of concealment is not described or not described in sufficient detail to allow a definite judgement, for example if the use of assignment envelopes is described, but it remains unclear whether envelopes were sequentially-numbered, opaque and sealed.

3. Blinding of participants and personnel - was knowledge of the allocated interventions adequately prevented during the study?

Low risk of bias: no blinding, but the review authors judge that the outcome and the outcome measurement are not likely to be influenced by lack of blinding, or blinding of participants and key study personnel ensured, and unlikely that the blinding could have been broken.

High risk of bias: no blinding or incomplete blinding, and the outcome is likely to be influenced by lack of blinding; or blinding of key study participants and personnel attempted, but likely that the blinding could have been broken, and the outcome is likely to be influenced by lack of blinding.

Unclear risk of bias: insufficient information to permit judgement of low or high risk of bias, or the study did not address this outcome.

4. Blinding of outcome assessment - was knowledge of the allocated interventions adequately prevented during the study?

Low risk of bias: no blinding of outcome assessment, but the review authors judge that the outcome measurement is not likely to be influenced by lack of blinding, or blinding of outcome assessment ensured, and unlikely that the blinding could have been broken.

High risk of bias: no blinding of outcome assessment, and the outcome measurement is likely to be influenced by lack of blinding; or blinding of outcome assessment, but likely that the blinding could have been broken, and the outcome measurement is likely to be influenced by lack of blinding.

Unclear risk of bias: insufficient information to permit judgement of low or high risk, or the study did not address this outcome.

5. Were incomplete outcome data adequately addressed?

Low risk of bias: no missing outcome data, or reasons for missing outcome data unlikely to be related to true outcome (for survival data, censoring unlikely to be introducing bias), or missing outcome data balanced in numbers across intervention groups, with similar reasons for missing data across groups; or (for dichotomous outcome data), the proportion of missing outcomes compared with observed event risk not enough to have a clinically relevant impact on the intervention effect estimate; or (for continuous outcome data), plausible effect size (difference in means or standardised difference in means) among missing outcomes not enough to have a clinically relevant impact on observed effect size; or missing data have been imputed using appropriate methods.

High risk of bias: reason for missing outcome data likely to be related to true outcome, with either imbalance in numbers or reasons for missing data across intervention groups; or (for dichotomous outcome data), the proportion of missing outcomes compared with observed event risk enough to induce clinically relevant bias in intervention effect estimate; or (for continuous outcome data), plausible effect size (difference in means or standardised difference in means) among missing outcomes enough to induce clinically relevant bias in observed effect size; or ‘as-treated’ analysis done with substantial departure of the intervention received from that assigned at randomisation, or potentially inappropriate application of simple imputation.

Unclear risk of bias: insufficient reporting of attrition/exclusions to permit judgement of low or high risk of bias (e.g. number randomised not stated, no reasons for missing data provided), or the study did not address this outcome.

6. Are reports of the study free of suggestion of selective outcome reporting?

Low risk of bias: either the RCT protocol is available and all of the pre-specified outcomes that are in the protocol have been reported in the pre-specified manner or, if the protocol is not available, it is clear that the published report includes all outcomes in the results section that are described as being assessed in the methods section.

High risk of bias: if the RCT protocol is available either, not all of the pre-specified outcomes that are in the protocol are reported, or one or more outcomes are reported using measurements, analysis methods or subsets of the data that are not pre-specified; or one or more reported outcomes were not pre-specified (unless there is justification for their reporting, such as an unexpected adverse event). If the RCT protocol is not available either, not all of the trial’s outcomes have been reported in the results section that are described in the methods section, or one or more of the outcomes is reported using measurements, analysis methods or subsets of the data (e.g. sub-scales) that were not described in the methods section of the report; or one or more of the reported outcomes were not described in the methods section.

Unclear risk of bias: insufficient information to permit judgement of low or high risk of bias.

What's new

DateEventDescription
26 June 2013AmendedExcluded study Meaume 2012, reason for exclusion clarified

Contributions of authors

Susan O'Meara: drafted the protocol, responded to the peer referee feedback and agreed the protocol, screened search results and selected relevant studies for inclusion, extracted data, performed risk of bias assessment, analysed data, generated Summary of Findings tables, drafted the review and responded to peer referee and copy editor comments.

Marrissa Martyn-St James: drafted the protocol, responded to the peer referee feedback for the protocol, screened search results and selected relevant studies to be included in the review, extracted data, performed risk of bias assessment and contributed to drafting the review and responding to peer referee comments.

Contributions of editorial base

Nicky Cullum: edited the protocol; advised on methodology, interpretation and protocol content. Approved the final protocol prior to submission.
Joan Webster, Editor: Approved the final review prior to submission.
Sally Bell-Syer: co-ordinated the editorial process. Advised on methodology, interpretation and content. Edited the protocol and review.
Ruth Foxlee: designed the search strategy and edited the search methods section.

Declarations of interest

This paper presents independent research funded by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research Programme (Grant Reference Number RP-PG-0407-10428). The views expressed are those of the authors (Susan O'Meara and Marrissa Martyn-St James) and not necessarily those of the NHS, the NIHR or the Department of Health.

Sources of support

Internal sources

  • Department of Health Sciences, University of York, UK.

External sources

  • NIHR Programme Grants for Applied Research, UK.

  • NIHR/Department of Health (England), (Cochrane Wounds Groups), UK.

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Andersen 2002

Methods

RCT across 4 European sites.

Country: Netherlands and Denmark.

Setting: outpatient clinics.

Sample size calculation: not reported.

Participants

118 patients recruited from outpatient clinics. 

Inclusion criteria: people with moderately- to highly-exuding venous or venous/arterial leg ulcers of at least 3 weeks' duration; primary aetiology venous insufficiency; and wound smaller than 9 cm x 9 cm.

Exclusion criteria: people < 18 years; pregnant women; ABPI < 0.8; insulin-dependent diabetes mellitus; erysipelas or other symptoms of clinical ulcer infection; or a history of cytotoxic or systemic steroid drug therapy during last 3 months.

 

Numbers randomised:

Group 1 (hydrocellular foam): 60 participants;

Group 2 (polyurethane foam): 58 participants.

 

Baseline variables were reported for participants completing the trial:

Group 1 (hydrocellular foam): n = 46;

Group 2 (polyurethane foam): n = 53.

 

Mean participant age (range):

Group 1 (hydrocellular foam): 72.0 (46-85) years;

Group 2 (polyurethane foam): 76.0 (30-92) years.

 

Number (%) male:

Group 1 (hydrocellular foam): 31/60 (67);

Group 2 (polyurethane foam): 33/58 (62).

 

Number (%) of venous leg ulcers:

Group 1 (hydrocellular foam): venous, 40 (87); mixed aetiology, 6 (13);

Group 2 (polyurethane foam): venous, 46 (87); mixed aetiology,7 (13).

 

Unit of analysis: participant.

 

Participant mobility, number (%) participants walking unaided vs walking aided vs wheelchair bound:

Group 1 (hydrocellular foam): 32/46 (70) vs 13/46 (28) vs 1/46 (2);

Group 2 (polyurethane foam): 35/53 (66) vs 14/53 (26) vs 4/53 (8).

 

Baseline ulcer area cm2 - mean (SD) [median (range)]:

Group 1 (hydrocellular foam): 7.23 (7.72) [4.22 (0.21-36.24)];

Group 2 (polyurethane foam): 5.19 (6.68) [2.83 (0.19-39.96)].

 

Baseline ulcer duration months - mean [median (range)]:

Group 1 (hydrocellular foam): 15.5 [6.0 (1.0-132)];

Group 2 (polyurethane foam): 14.3 [6.0 (0.75-120)].

 

Ulcer infection:

Not eligible to participate with erysipelas or other symptoms of clinical ulcer infection.

 

Participant baseline exudate levels:

Group 1 (hydrocellular foam): 40/46 (87%) participants had moderate exudate, 6/46 (13%) had heavy exudate.

Group 2 (polyurethane foam): 47/53 (89%) participants had moderate exudate, 6/53 (11%) had heavy exudate.

Interventions

Group 1: hydrocellular foam dressing (Allevyn, Smith and Nephew);

Group 2: polyurethane foam dressing (Biatain, Coloplast).

Wounds rinsed with isotonic saline solution. Periulcer skin treatments (e.g. zinc oxide paste or topical corticosteroids) used according to the standard procedure in the individual clinic. Both dressings could be secured with a secondary absorbent dressing and an elastic bandage at the discretion of the investigator. Dressings changed once every 7 days, if leakage occurred, or when an interim assessment was deemed necessary. Participants assessed every 7 days until ulcer completely healed or study period completed.

 

Description of compression therapy: short-stretch compression bandage changed once or twice a week, depending on the amount of oedema and exudate.

 

Length of treatment: 8 weeks, or until healing. 

Length of follow up: 8 weeks.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: healing assessed by tracing ulcer area and calculating ulcer size (planimetry).

Proportion of ulcers healed: assessed as time to healing.

Change in ulcer size: assessed as time to healing.

Healing rate: not reported.

Adverse events: peri-ulcer skin reactions (maceration, erythema, eczema, and petechiae) assessed using VRS ("none," "little," "moderate," or "severe").

Quality of life: not reported.

Cost: average material costs/participant/week (including costs of dressings, unclear if bandages and other treatment materials included, not including nursing time).

Pain: participants asked to describe experience of pain in ulcer area as "none," "little," "moderate," or "severe" at weekly assessments.

Dressing performance: ability of dressings to handle exudate assessed by recording incidence of leakage (yes/no), number of dressing changes/week, and extent of peri-ulcer skin reactions. Dressing absorption capacity rated using a VRS ("excellent," "good," "reasonable," or "poor"); peri-ulcer skin reactions (maceration, erythema, eczema, and petechiae) assessed using a VRS ("none," "little," "moderate," or "severe").

Other outcomes assessed by the trial: percentage changes in black necrotic, yellow slough, and healthy red granulation tissue in the wound bed; dressing comfort and odour.

Notes

Sponsor: Coloplast (trial number not reported). 

Number (%) of participants withdrawing and reasons:

Group 1 (hydrocellular foam): 14/60 (23) adverse events: maceration/erythema/secondary infected dermatitis = 1; erysipelas = 1.

Serious adverse events: hospitalisation (pain) = 1; prolonged hospitalisation (cardiac event) = 1; death (acute MI) = 1.

Other medication used = 6. Protocol violation (ulcer size exceeded maximum specified in protocol) = 2. Withdrew consent = 1

Group 2 (polyurethane foam):  5/58 (9) adverse events: maceration/erythema/secondary infected dermatitis = 1; pain after dressing application = 1.

Other medication used = 2. Protocol violation (ulcer size exceeded maximum specified in protocol) = 1.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

Quote: “Subjects were randomised in blocks of six to one of the two treatment groups using sequentially numbered, sealed opaque envelopes.”

Comment: sequence generation not reported.

Allocation concealment (selection bias)Low risk

Quote: “Subjects were randomised in blocks of six to one of the two treatment groups using sequentially numbered, sealed, opaque envelopes.”

Comment: allocation process adequate.

Blinding of participants and personnel (performance bias)
All outcomes
High risk

Quote: “Because the study was not blinded, secondary absorbent dressing and peri ulcer treatments used were at the discretion of the investigator.”

Comment: stated as not being blinded.

Blinding of outcome assessment (detection bias)
All outcomes
High risk

Quote: “Because the study was not blinded, secondary absorbent dressing and peri ulcer treatments used were at the discretion of the investigator.”

Comment: stated as not being blinded.

Incomplete outcome data (attrition bias)
All outcomes
High riskComment: numbers withdrawing and reasons reported by group (Group 1: 14/60 (23%); Group 2: 5/58 (9%)) but a higher proportion of participants withdrew from Group 2 and analysis not undertaken as ITT.
Selective reporting (reporting bias)Unclear riskComment: although all trial outcomes described in the published report are in the supplied RCT protocol, it was unclear from the published report what the primary outcomes were (maceration in the protocol). A secondary outcome of ‘ability to adapt’ in the protocol (translated from Danish) is not identifiable in the published report.

Andriessen 2009

Methods

RCT, pilot study.

Country: Italy.

Setting: phlebology clinic.

Sample size calculation: as this was a pilot study, sample size was not based on statistical considerations.

Participants

12 patients recruited from a phlebology clinic.

Inclusion criteria: people aged > 18 years; transcutaneous oxygen (TcPO2) level < 40 mmHg; venous leg ulcers that had not reduced in size after 4 weeks of standard treatment (i.e. a primary dressing plus compression). Ulcer aetiology assessed before entry into the study using a hand-held Doppler, Duplex sonography and digital photoplethysmography.

Exclusion criteria: venous leg ulcers with clinical signs of infection (redness, swelling, increased pain, increased exudation), necrotic tissue or a predominance of slough; significant arterial disease (APBI < 0.8); ulcers < 4 cm² and circumferential ulcers; ulcers of non-venous aetiology; other causes of ulceration (rheumatoid vasculitis, diabetic foot ulceration, malignant ulceration); use of oral and/or topical corticosteroids; participation in a leg ulcer trial within last 12 months; dementia or disorientation; or a known allergy to latex or other contents of the trial products. When a person had more than 1 ulcer, the largest was evaluated in the trial.

 

Numbers randomised:

Group 1 (paraffin gauze): 4 participants;

Group 2: (protease-modulating matrix dressing): 4 participants;

Group 3 (polyurethane foam): 4 participants.

 

Mean (range) participant age:

Group 1 (paraffin gauze): 76.5 (74-79) years;

Group 2: (protease-modulating matrix  dressing): 79.0 (70-91) years;

Group 3 (polyurethane foam): 78.3 (70-81) years.

 

Number (%) male:

Overall sample: 4/12 (33).

 

Unit of analysis: participant. 

Participant mobility: not reported.

 

Baseline ulcer area cm2 - mean (range):

Group 1 (paraffin gauze): 17.4 (8.5-29);

Group 2: (protease-modulating matrix  dressing): 24.0 (12.4-56);

Group 3 (polyurethane foam): 27.6 (16-62).

 

Baseline ulcer duration months - mean [median (range)]:

Group 1 (paraffin gauze): 26.3 [11 ( 4-84)];

Group 2: (protease-modulating matrix  dressing): 7.8 [9 (4-14 )];

Group 3 (polyurethane foam): 11.3 [14 (4-22)].

 

Ulcer infection: people with venous leg ulcers with clinical signs of infection were excluded.

 

Participants ulcer history: not reported. 

Participant baseline wound exudate levels: not reported.

Interventions

Group 1: paraffin gauze (brand name and manufacturer not reported).

Group 2: protease-modulating matrix dressing (Suprasorb C, Lohmann & Rauscher) with foam dressing (Suprasorb P, Lohmann & Rauscher) as secondary dressing.

Group 3: polyurethane foam (Suprasorb P, Lohmann & Rauscher).

Wounds cleansed with saline. Dressing change frequency at clinician’s discretion, but on average twice weekly, based on exudate levels only. Wounds assessed on days 0 (baseline) 14 and 18.

 

Description of compression therapy: all patients wore short-stretch high compression bandages (Rosidal K, Lohmann & Rauscher) that included a foam layer. This was changed, on average, twice weekly.

 

Length of treatment: 4 weeks. 

Length of follow up: 4 weeks.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: not reported.

Proportion of ulcers healed: not reported.

Change in ulcer size: ulcers photographed with a high-resolution digital camera and wound edges traced using a squared grid (4 squares/cm).

Healing rate: not reported.

Adverse events: clinician recorded severity and timing of any adverse events, plus action taken, on days 0, 7, 14, 21 and 28.

Quality of life: not reported.

Cost: not reported.

Pain: participants reported pain at each dressing removal on a 10 cm visual analogue scale (VAS).

Dressing performance: assessed adherence to the wound.

Other outcomes assessed by the trial: changes in wound bed characteristics; TcPO2 measurements; video laser Doppler measurements of skin perfusion; number of capillaries in the ulcer bed; participant compliance.

Notes

Sponsor: Lohmann & Rauscher (trial number not reported).

Number of participants withdrawing and reasons: trialists reported that all recruited participants completed the trial. 

Trial undertaken as a pilot study.  Full trial was not undertaken due to ethical issues (email communication with trial author).

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk

Quote: “Patients were randomised by a computer-generated allocation scheme, using sealed envelopes, to one of three treatments.”

Comment: sequence generation adequate.

Allocation concealment (selection bias)Unclear risk

Quote: “Patients were randomised by a computer-generated allocation scheme, using sealed envelopes, to one of three treatments.”

Comment: not stated whether envelopes were opaque and sequentially-numbered.

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskComment: no statement regarding blinding of participants or study personnel.
Blinding of outcome assessment (detection bias)
All outcomes
Low risk

Quote: “Assessors were blinded to the treatment given for all of these tests.”

Comment: assessor blinding adequate.

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Quote: “Twelve patients were recruited into and completed this pilot RCT”.

Comment: no dropouts and all participants included in final analysis.

Selective reporting (reporting bias)Low risk

Comment: all trial outcomes described in the methods section of the report were included in the results section.

Unable to obtain RCT protocol.

Banerjee 1990

Methods

RCT.

Country: England, UK.

Setting: In-patients and day hospital for the elderly.

Sample size calculation: not reported.

Participants

71 people recruited from in-patients or people attending day hospital for the elderly.

No specific inclusion or exclusion criteria reported, although a limb X-ray and biopsy taken initially, and Doppler readings used to exclude significant peripheral vascular disease.

 

Numbers randomised:

Group 1 (paraffin gauze): 35 participants;

Group 2 (polyurethane foam): 36 participants.

 

Mean participant age (SD):

Group 1 (paraffin gauze): 81.2 (7.3) years;

Group 2 (polyurethane foam): 75.9 (7.7) years.

 

Number (%) male:

Group 1 (paraffin gauze): 7/35 (20);

Group 2 (polyurethane foam): 7/36 (19).

 

Unit of analysis: participant.

 

Number (%) participants with locomotor problems:

Group 1 (paraffin gauze): 30/35 (86);

Group 2 (polyurethane foam): 26/36 (72).

No specific details reported regarding the type or severity of locomotor problems.

 

Baseline ulcer area cm2 - median (range):

Group 1 (paraffin gauze): 11.4 (1.3-134.0), n = 33;

Group 2 (polyurethane foam): 12.2 (1.1-138.0), n = 34.

 

Baseline ulcer duration:

Trialists reported that time since onset was approximately 2 years in both groups. No data presented by group.

 

Number (%) of infected ulcers:

Group 1 (paraffin gauze): 21/35 (60);

Group 2 (polyurethane foam): 29/36 (81).

These ulcers regarded as infected by trialists. Bacteriology swabs taken, however, no definition of infection or details of bacteriology assessment reported.

 

Number (%) participants with recurrent ulcers:

Group 1 (paraffin gauze): 14/35 (40);

Group 2 (polyurethane foam): 14/36 (39).

 

Participant baseline exudate levels: not reported.

 

Comments: trialists reported that all participants were either taking concurrent medication and/or suffering from other medical disorders. The most common problems were heart diseases, arthritis and cerebrovascular disorders. This information was not reported by treatment group.

Interventions

Group 1: paraffin gauze (Paratulle, Seton Healthcare);

Group 2: polyurethane foam (Synthaderm, Armour).

Wounds cleaned with warm saline. Both dressings applied under a backing pad (details not reported) and contour bandaging (K-band, Parema). Participants assessed weekly by the same individual.

 

Description of compression therapy: trialists did not report use of compression therapy in either group.

Length of treatment: 17 weeks, or until healing of the ulcer occurred. 

Length of follow up: 17 weeks.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: not reported.

Proportion of ulcers healed: photographs and surface area tracings taken at weeks 4, 8, 12 and 17. Evidence of healing relative to previous treatment assessed each week on a 5-point scale (1 = completely healed, 5 = marked deterioration).

Change in ulcer size: see above.

Healing rate: not reported.

Adverse events: not reported.

Quality of life: not reported.

Cost (resources used): recorded total number of dressings required each week.

Pain: ulcer pain assessed on a 4-point scale weekly. No details reported about the scale, or when pain was assessed in relation to wound dressing.

Dressing performance: not reported.

Other outcomes assessed by the trial: infection; oedema.

Notes

Sponsor: sponsor and trial number not reported. 

Number (%) of participants withdrawing and reasons:

Group 1 (paraffin gauze): 11/35 (31); died = 3; lack of efficacy = 4; reason not stated = 4;

Group 2 (polyurethane foam): 8/36 (22); died = 7; reason not stated = 1.

 

Participants not included at week 17 ulcer area assessment:

Group 1: 21/35 (60%);

Group 2: 20/34 (56%).

 

Trialists did not report reasons for participant exclusion from analysis of ulcer area (apart from those who withdrew - see above).

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

Quote: “Treatment allocation was random”.

Comment: sequence generation not reported.

Allocation concealment (selection bias)Unclear risk

Quote: “Treatment allocation was random”.

Comment: allocation process not reported.

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskComment: no statement made regarding blinding of participants or study personnel.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear risk

Quote: “Photographs and surface area traces were taken at baseline and at weeks 4, 8, 12, 17 . . . Bacteriology swabs were also taken at these time points. Assessments of severity of ulcer pain and the presence of oedema were recorded weekly.”

Comment: no statement made regarding blinded outcome assessment.

Incomplete outcome data (attrition bias)
All outcomes
High riskComment: number of patients that withdrew from each group stated, but reasons for withdrawal - other than lack of efficacy - not reported. No statement regarding why some participants, other than those reported as withdrawals, were not included at ulcer size assessment follow up.
Selective reporting (reporting bias)Low risk

Comment: all trial outcomes described in the methods section of the report were included in the results section.

Unable to obtain RCT protocol.

Bowszyc 1995

Methods

Single-centred RCT.

Country: Poland.

Setting: dermatology clinic.

Sample size calculation: not reported.

Participants

80 patients recruited from a dermatology clinic in Poznan, Poland.

Inclusion criteria: people > 18 years suffering from chronic leg ulcers.

Exclusion criteria: leg ulcers suspected to be due to arterial insufficiency (ABPI < 0.80); diabetes; heavily exuding wounds; necrotic tissue present in the ulcer; clinically infected wounds; a general poor state of health; and those who were immuno-suppressed or receiving corticosteroid treatment.

 

Numbers randomised:

Group 1 (hydrocolloid): 40 participants;

Group 2 (polyurethane foam):40 participants.

 

Mean participant age (SD):

Group 1 (hydrocolloid): 55.5 years (14.7);

Group 2 (polyurethane foam): 64.2 years (14.4).

 

Number (%) male:

Group 1 (hydrocolloid): 15/40 (38);

Group 2 (polyurethane foam): 12/40 (30).

 

Unit of analysis: leg (2 participants had bilateral leg ulcers):

Group 1 (hydrocolloid): 41 legs;

Group 2 (polyurethane foam): 41 legs.

Unit of randomisation: participant.

 

Participant mobility - number (%) completely mobile vs less than completely mobile:

Group 1 (hydrocolloid): 35/40 (88) vs 5/40 (13);

Group 2 (polyurethane foam): 28/40 (70) vs 12/40 (30).

 

Baseline ulcer area cm2 - mean (SD):

Group 1 (hydrocolloid): 3.5 (7.8);

Group 2 (polyurethane foam): 4.0 (6.9).

 

Baseline ulcer duration (reported as weeks in the primary reference and as months in the secondary reference for the trial) - mean (SD):

Group 1 (hydrocolloid): 36.1 (70.9);

Group 2 (polyurethane foam): 26.2 (37.6).

 

Ulcer infection:

People with clinically infected wounds were excluded. 

Participant ulcer history: not reported.

 

Participant baseline exudate levels:

People with heavily exuding ulcers were excluded.

Interventions

Group 1: hydrocolloid (Granuflex,ConvaTec);

Group 2: polyurethane foam(Lyofoam, Seton Healthcare).

Dressings changed weekly or when exudate leaked visibly through the bandage covering the dressing. Sloughy wounds treated with an NaCl solution containing 0.3%-0.4% available chlorine (Chlorasol) before entry into the trial.

 

Description of compression therapy: used a high-compression bandage (Setopress), applied to achieve 40 mmHg at the ankle, with both dressings.

 

Length of treatment: 16 weeks, or until ulcer had healed. 

Length of follow up: 16 weeks.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: ulcer area measured every week using a transparent grid and by measuring ulcer's length and breadth. Ulcers photographed every 4 weeks.

Proportion of ulcers healed: assessed as time to healing.

Change in ulcer size: not reported.

Healing rate: not reported.

Adverse events: mentioned briefly but unclear how assessed.

Quality of life: not reported.

Cost: UK Drug Tariff price/dressing reported and weekly number of dressing changes recorded.

Pain: participants asked to score pain on dressing removal on a scale of 1-4 (1 = very painful and 4 = no pain) at the end of the trial.

Dressing performance: nurse-rated ease of dressing removal. Although not explicitly stated, the same scale appeared to have been used as that for ease of dressing application (scale of 0-10 where 0 = easy to apply and 10 = difficult to apply, assumed 0 = easy to remove and 10 = difficult to remove).

Other outcomes assessed by the trial: ease of dressing application; dressing comfort.

Notes

Sponsor: Seton Healthcare Group (trial number not reported).

 

Number of withdrawals (not reported whether participants or legs):

Group 1 (hydrocolloid): 4;

Group 2 (polyurethane foam): 4.

 

Reasons for withdrawal given overall, but not by group: personal reasons = 3; localised infection requiring antibiotic and surgical treatment = 2; allergic reaction requiring corticosteroids = 1; increased volume of wound exudate = 1; severe lower limb pain = 1.

 

5 participants excluded because of heavily exuding wounds (numbers not reported by group and not stated whether withdrawal occurred pre- or post-randomisation).

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

Quote: “Patients were allocated to treatment according to a pre-prepared randomisation listing.”

Comment: insufficient detail provided to judge whether the method of randomisation was satisfactory.

Allocation concealment (selection bias)Unclear risk

Quote: “Patients were allocated to treatment according to a pre-prepared randomisation listing.”

Comment: allocation process not reported.

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskComment: no statement made regarding blinding of participants or study personnel.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear risk

Quote: “At each dressing change, the state of the ulcer and surrounding skin was assessed and the nurse also observed the ease of removal and application of the dressing.”

Comment: no statement made regarding blinded outcome assessment.

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Quote: “Four patients in each group withdrew from the study.”

Comment: tabulated information suggested that all legs were included in the analyses. 

Selective reporting (reporting bias)High risk

Comment: average number of dressings used/week reported in results, but assessment not included in methods section.

Unable to obtain RCT protocol.

Callam 1992

Methods

RCT with factorial design to allow concurrent evaluation of 2 compression bandages and 2 dressings, provided no interaction existed between dressings and bandages.

Country: Scotland, UK.

Setting: leg ulcer clinics.

Sample size calculation: not reported.

Participants

132 patients recruited from 2 hospital leg ulcer clinics.

Inclusion criteria: patients referred to leg ulcer clinics.

Exclusion criteria: ABPI < 0.8; diabetes; or seropositive rheumatoid arthritis.

 

Numbers randomised:

Group 1 (knitted viscose): 66 participants;

Group 2 (hydrocellular foam): 66 participants.

 

Mean participant age:

Group 1 (knitted viscose): 63 years;

Group 2 (hydrocellular foam): 64 years.

 

Number (%) male:

Group 1 (knitted viscose): 30/63 (45);

Group 2 (hydrocellular foam): 29/64 (44).

 

Unit of analysis: participant. For participants with bilateral leg ulcers, only 1 leg was entered into the trial. Did not report how reference wound was selected.

Participant mobility: not reported.

 

Mean ABPI:

Group 1 (knitted viscose): 1.2;

Group 2 (hydrocellular foam): 1.2.

 

Mean baseline ulcer area cm2:

Group 1 (knitted viscose): 8.35;

Group 2 (hydrocellular foam): 10.87.

 

Mean baseline ulcer duration months:

Group 1 (knitted viscose): 11.2;

Group 2 (hydrocellular foam): 11.7.

 

Number (%) participants with ulcer duration < 6 months vs 6-11 months vs 1-2 years vs ≥ 3 years:

Group 1 (knitted viscose): 31 (47) vs 18 (27) vs 11 (17) vs 6 (9);

Group 2 (hydrocellular foam): 33 (50) vs 18 (30) vs 14 (21) vs 1 (2).

 

Number (%) participants with previous leg ulcer history:

Group 1 (knitted viscose): 50/66 (76);

Group 2 (hydrocellular foam): 40/66 (61).

 

Participant baseline exudate levels:  not reported.

Interventions

Group 1: knitted viscose (Tricotex, Smith and Nephew);

Group 2: hydrocellular foam (Allevyn, Smith and Nephew).

No details about wound cleansing or other aspects of wound care. Participants assessed at least weekly. No report of number of participants allocated to each dressing and bandage combination. No statistical interaction detected between dressings and bandages (P = 0.87).

Description of compression therapy: participants randomised to 2 types of compression bandages, described as “elastic” and “non-elastic” multi-layer bandage systems. The elastic system consisted of: orthopaedic padding (Soffban Natural); elastic bandage (Tensopress); and elastic graduated tubular bandage (Tensoshape). Non-elastic system consisted of: orthopaedic padding (Soffban Natural); cotton crepe bandage (Elastocrepe); and a limited-stretch cohesive bandage (Tensoplus Forte). All bandages applied by experienced research nurses using a standardised spiral technique rehearsed before the trial started.

 

Length of treatment: 12 weeks or until the ulcer healed, whichever occurred sooner. Tracings of ulcers taken at 0, 4, 8 and 12 weeks. 

Length of follow up: 12 weeks.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: ulcer areas traced onto a clear plastic film, then measured using computer software.

Proportion of ulcers healed: assessed as time to healing.

Change in ulcer size: assessed as time to healing.

Healing rate: not reported.

Adverse events: reported number of participants with skin complications.

Quality of life: not reported.

Cost: not reported.

Pain: assessed, but method not reported.

Dressing performance: not reported.

Other outcomes assessed by the trial: appearance of the ulcer (slough and granulation).

Notes

Sponsor: Health Service Research Committee of the Scottish home and Health Department. Smith and Nephew provided bandages and dressings. Trial number not reported.

 

Number (%) of participants withdrawing:

Group 1 (knitted viscose): 15/51 (29);

Group 2 (hydrocellular foam): 13/53 (25).

 

Reasons for withdrawal - some participants had more than one reason:

Group 1 (knitted viscose): sensitivity = 2; exudate = 6; deterioration (not stated if ulcer or patient) = 12; social = 1; other = 6;

Group 2 (hydrocellular foam): sensitivity = 8; exudate = 7; deterioration = 12; social = 1; other = 4.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

Quote: “After consent, the patients were randomised to either an elastic or non-elastic bandage regimen. They were also randomised to either a knitted viscose dressing (Tricotex) or a hydrocellular dressing (Allevyn) in such a way that there were equal numbers of each type of dressing in both the elastic and non-elastic group.”

Comment: sequence generation not reported.

Allocation concealment (selection bias)Unclear risk

Quote: “After consent, the patients were randomised to either an elastic or non-elastic bandage regimen. They were also randomised to either a knitted viscose dressing (Tricotex) or a hydrocellular dressing (Allevyn) in such a way that there were equal numbers of each type of dressing in both the elastic and non-elastic group.”

Comment: allocation process not reported.

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskComment: no statement regarding blinding of participants or study personnel.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskComment: no statement regarding blinded outcome assessment.
Incomplete outcome data (attrition bias)
All outcomes
High riskComment: reasons for withdrawal were presented by group, but more than one reason could be given for an individual patient. Numbers withdrawing balanced across groups (Group 1: 15/66 (23%); Group 2: 13/66 (20%)), but missing data not accounted for in final analysis using ITT.
Selective reporting (reporting bias)Low riskComment: protocol was available; all outcomes specified in the protocol were reported.

Charles 2002

Methods

RCT.

Country: UK.

Setting: hospital leg ulcer clinic.

Sample size calculation: not reported.

Participants

91 patients recruited from a hospital leg ulcer clinic.

Inclusion criteria: people with venous leg ulcers 2 cm-12 cm at widest perpendicular diameter; ABPI ≥ 8.0; ambulatory; >18 years; and able to provide consent. Venous leg ulcer aetiology defined in terms of an ABPI ≥ 0.8, in tandem with ulcer location and clinical judgement.

Exclusion criteria: receiving corticosteroids or on corticosteroids within the last 2 months; insulin dependence; allergies to test products; history of radiation or cytotoxic treatment near ulcer site; primary arterial occlusive disease; registered alcoholics; unwilling or unable to provide informed consent; known HIV-positive; or unlikely to comply with treatment for psychological or physical reasons.

Assessment of ulcer size and ulcer-associated pain performed fortnightly after enrolment.

 

Numbers randomised:

Group 1 (hydrocolloid, Comfeel): 29 participants;

Group 2 (hydrocolloid, Granuflex): 31 participants;

Group 3 (polyurethane foam):31 participants.

 

Mean participant age (range):

Group 1 (hydrocolloid, Comfeel): 72 (56-85);

Group 2 (hydrocolloid, Granuflex): 72 (53-91);

Group 3 (polyurethane foam): 71 (53-84).

 

Number (%) male:

Group 1 (hydrocolloid, Comfeel): 13/29 (45);

Group 2 (hydrocolloid, Granuflex): 12/31 (39);

Group 3 (polyurethane foam): 15/31 (48).

 

Unit of analysis: participant. 

Participant mobility: trialists reported that all participants were ambulatory.

Baseline ulcer area mm2 - mean (range)

Group 1 (hydrocolloid, Comfeel):1035 (205-3795);

Group 2 (hydrocolloid, Granuflex): 930 (234-3642);

Group 3 (polyurethane foam): 881 (271-318).

Baseline ulcer duration weeks - mean (range):

Group 1 (hydrocolloid, Comfeel):104 (3-1040);

Group 2 (hydrocolloid, Granuflex): 95 (1-1560);

Group 3 (polyurethane foam): 137 (4-1560).

 

Ulcer infection: not reported.

 

Number (%) of participants reporting ulcer pain:

Group 1 (hydrocolloid Comfeel): 19/29 (65.5);

Group 2: (hydrocolloid Granuflex): 19/31 (61.3);

Group 3 (polyurethane foam): 24/31 (77.4).

Trialists only reported the percentage of participants reporting pain. The raw numbers presented here were extrapolated by the review authors.

 

Mean baseline ulcer-associated pain score across 0-10 visual analogue scale (VAS):

Group 1 (hydrocolloid, Comfeel): 3.83;

Group 2 (hydrocolloid, Granuflex): 3.81;

Group 3 (polyurethane foam): 4.77.

Trialists reported that 70% of all participants experienced mid to lower-mid range pain severity assessed using both a VAS and the McGill Pain Questionnaire.

Participant ulcer history: not reported.

Participant baseline exudate levels: not reported.

Interventions

Group 1: hydrocolloid (Comfeel, Coloplast);

Group 2: hydrocolloid (Granuflex new formulation,Convatec);

Group 3: polyurethane foam (Cutinova, Beiersdorf later BSN Medical).

All dressings applied according to the manufacturer’s instructions. Primary dressings changed as frequently as necessary. All ulcers, regardless of primary dressing, were secondarily dressed with padding on bony prominences

 

Description of compression therapy: short-stretch compression bandaging (Comprilan).

 

Length of treatment: 12 weeks, or until healing (complete epithelialisation) .

Length of follow up: 12 weeks.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: computer-assisted planimetry used to estimate ulcer area from acetate tracings.

Proportion of ulcers healed: assessed as time to healing.

Change in ulcer size: assessed as time to healing. The ulcer area remaining at each assessment was expressed as a percentage relative to baseline area.

Healing rate: not reported.

Adverse events: reported briefly, but no mention of assessment methods.

Quality of life: not reported.

Cost: not reported.

Pain: participants asked to score ulcer-associated pain using a 0-10 VAS, where 0 = no pain and 10 = severe pain. The McGill Pain Questionnaire (MPQ-PPI) was also used.

Dressing performance: ease of dressing removal assessed by nurses using a 5-point scale (1 = very easy, 2 = easy, 3 = no difficulty, 4 = difficult, 5 = very difficult), at 6 weeks and 12 weeks, or on last dressing for healed ulcers.

Other outcomes assessed by the trial: ease of dressing use and ease of application.

Notes

Sponsor: Beiersdorf later BSN Medical (trial number not reported).

 

Number (%) of participants withdrawing:

Group 1 (hydrocolloid, Comfeel): 1/29 (3);

Group 2 (hydrocolloid, Granuflex): 4/31 (13);

Group 3 (polyurethane foam): 1/31 (3).

Trialists reported that all withdrawals were for medical reasons unrelated to the study, no other details were provided.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk

Quote: “Once enrolled, patients were randomly allocated to one of three treatment (primary dressing) groups . . . using a minimization method derived from that of Pocock and Simon (1975)”.

Comment: sequence generation adequate.

Allocation concealment (selection bias)Unclear risk

Quote: “Once enrolled, patients were randomly allocated to one of three treatment (primary dressing) groups”.

Comment: allocation process not reported.

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskComment: no statement regarding blinding of participants or study personnel.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskComment: no statement regarding blinded outcome assessment.
Incomplete outcome data (attrition bias)
All outcomes
High riskComment: although all participants were included in healing analyses (ITT), not all recruited participants were included in the analyses of secondary outcomes.
Selective reporting (reporting bias)High risk

Comment: trialists reported that no adverse events occurred, but did not report adverse events assessment in the methods section.

Unable to obtain RCT protocol.

Franks 2007

Methods

Multicentred RCT (12 centres) with factorial design to allow concurrent evaluation of 2 compression bandages and 2 dressings.

Country: England, UK.

Setting: clinical services.

Sample size calculation: original sample size estimated at 200 patients based on 80% of ulcers healing over 24 weeks. Clinical improvement was defined as an increased healing rate of 15% (90% power and level of significance of 5%). Owing to change in entry criterion (maximum ulcer duration originally set at 24 weeks, but following a trial amendment, increased to 52 weeks), the baseline healing rate was reduced to 70% with a corresponding increase in sample size of 240. Logistical difficulties resulted in the recruitment period being extended from 1-2 years. 159 participants were recruited (156 evaluable), reducing power to 81%.

Participants

159 patients recruited from clinical services.

Inclusion criteria: ≥ 18 years of age; with chronic venous ulceration and showing signs and symptoms of venous disease; ABPI ≥ 0.8; minimum ulcer duration 2 weeks. Initially, maximum ulcer duration set at 24 weeks, but following a trial amendment, increased to 52 weeks. Photoplethysmography confirmed diagnosis of venous ulceration post-randomisation.

Exclusion criteria: causes of ulceration other than venous disease based on clinical presentation; pregnancy; active cellulitis requiring systemic antibiotics; and non-exuding wounds.

 

Baseline characteristics reported for 156/159 (98%) evaluable participants.

 

Numbers randomised:

Group 1 (polyurethane foam): 75 participants;

Group 2 (hydrocellular foam):81 participants.

 

Mean participant age (SD):

Group 1 (polyurethane foam): 69.2 years (13.4);

Group 2 (hydrocellular foam): 69.3 years (14.5).

 

Number (%) male:

Group 1 (polyurethane foam): 29/75 (38.7)

Group 2 (hydrocellular foam): 32/81 (39.5)

 

Baseline ABPI – median (range):

Group 1 (polyurethane foam): 1.12 (0.82-1.50);

Group 2 (hydrocellular foam): 1.10 (0.80-2.00).

 

Unit of analysis: participant.

Patients with bilateral ulceration were randomised to 1 dressing and 1 bandage system only. The reference limb was that with the largest ulcer area at baseline.

 

Participant mobility – number (%) chair/bed bound vs walking with aid vs walking freely:

Group 1 (polyurethane foam): 1/75 (1.3) vs 14/75 (18.7) vs 60/75 (80.0);

Group 2 (hydrocellular foam): 0/81 (0) vs 18/81 (22.2) vs 63/81 (77.8).

 

Participant limb mobility – number (%) fully mobile vs limited mobility vs fixed:

Group 1 (polyurethane foam): 60/75 (81.1) vs 13/75 (17.6) vs 1/75 (1.4);

Group 2 (hydrocellular foam): 67/81 (82.7) vs 13/81 (16.0) vs 1/81 (1.2).

 

Baseline ulcer area cm2 – number (%) ≤ 10 cm2 vs > 10 cm2:

Group 1 (polyurethane foam): 60/75 (80.0) vs 15/75 (20.0);

Group 2 (hydrocellular foam): 66/81 (81.5) vs 15/81 (18.5).

 

Baseline ulcer duration weeks - median (range):

Group 1 (polyurethane foam): 8 (2-40);

Group 2 (hydrocellular foam): 8 (2-36).

 

Ulcer infection:

People with active cellulitis who were receiving systemic antibiotics were excluded.

 

Pre-dressing pain at baseline (VAS) – median (interquartile range):

Group 1 (polyurethane foam): 3.4 (4.0), n = 67;

Group 2 (hydrocellular foam): 3.6 (4.7), n = 71.

 

Post-dressing pain at baseline (VAS) – median (interquartile range):

Group 1 (polyurethane foam): 2.5 (4.0), n = 66;

Group 2 (hydrocellular foam): 2.5 (4.0), n = 69.

 

McGill Pain Questionnaire sensory pain scores – median (interquartile range):

Group 1 (polyurethane foam): 3.0 (6.0), n = 66;

Group 2 (hydrocellular foam): 3.0 (8.0), n = 71.

 

McGill Pain Questionnaire affective pain scores – median (interquartile range):

Group 1 (polyurethane foam): 0.0 (1.0), n = 62;

Group 2 (hydrocellular foam): 0.0 (1.0), n = 66.

 

Number (%) participants with previous ulceration:

Group 1 (polyurethane foam): 31/75 (41.3);

Group 2 (hydrocellular foam): 26/81 (32.5).

 

Participant baseline exudate levels: not reported, but dry wounds were excluded.

Interventions

Group 1: silicone-faced polyurethane foam dressing (Mepilex, Mölnlyke Health Care);

Group 2: hydrocellular foam dressing (Allevyn, Smith and Nephew).

Standard regimen: limb washed using an emollient dissolved in tap water, wound debrided (simple mechanical debridement to remove slough and dead tissue), and a simple hypoallergenic cream applied to hydrate the skin. Redressing and re-bandaging undertaken weekly unless required more frequently on clinical grounds. Participants with ulcer closure during trial were provided with class II compression hosiery (Activa Healthcare) and followed up until 24 weeks.

 

Description of compression therapy: limbs bandaged using either a 4-layer bandage system (Flexiban, Setocrepe, Elset and Coban) or a cohesive short-stretch system (Flexiban and Actico).

 

Proportion (%) of participants randomised to 4-layer vs short-stretch bandaging regimen:

Group 1 (polyurethane foam): 46.7% vs 53.3%;

Group 2 (hydrocellular foam): 48.1% vs 51.9%.

 

Length of treatment: 24 weeks. 

Length of follow up: 24 weeks, even if the ulcer had healed.

 

Comments: as the trial was factorial in design, the selection of primary dressing and bandage system were both on the basis of the randomisation procedure. Patients who withdrew from the bandage trial but continued to receive the randomised dressing continued to be followed up within the dressing trial.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: estimated using Cox proportional hazards model adjusting for dressing, bandage and study centre in an initial model; a further model adjusted for bandage, baseline ulcer area (< or ≥ 10 cm2), baseline ulcer duration (< or ≥ 6 months) and general mobility (walking unaided vs walking with aid vs chair/bed bound).

Proportion of ulcers healed: ulcer closure defined as complete epithelialisation of the reference limb.

Change in ulcer size: not reported.

Healing rate: not reported.

Adverse events: all adverse events detailed on an adverse incident form and reasons for withdrawal ascertained wherever possible.  Device-rated adverse events classified as: tissue damage; pain; maceration; and other.

Quality of life: not reported.

Cost: not reported.

Pain: participants questioned about pain at baseline and week 4 dressing visit using the short form McGill pain questionnaire. A VAS was used to assess intensity of pain before dressing removal, and following redressing and bandaging.

Dressing performance: not reported.

Other outcomes assessed by the trial: none.

Notes

Sponsor: Mölnlyke Health Care AB and Activa Health Care (trial number not reported).

 

Discovered post-randomisation that 3 participants did not meet the trial inclusion criteria (2 had ABPI < 0.8 and 1 did not give informed consent) and were excluded from analyses.

 

Number (%) of participants withdrawing and reasons:

Group 1 (polyurethane foam): 23/75 (30.7): adverse event = 17; lost to follow up = 5; bandage-related withdrawal = 1.

Group 2 (hydrocellular foam): 24/81 (29.6): died = 1; adverse event = 14; patient request = 2; lost to follow up = 5; bandage-related withdrawal = 2.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low risk

Quote: “At each center there were two randomisation lists, one for patients with a total area of ulceration on the reference limb of ≤ 10 cm2, and one with total area > 10 cm2. Separate randomisation lists were used in all centers”.

Comment: judgement of low risk taken following personal communication with trialists in connection with a separate review.

Allocation concealment (selection bias)Low risk

Quote: “Randomization took place following consent and eligibility checks, by means of opening sealed envelopes in a sequential order”.

Comment: judgement of low risk taken following personal communication with trialists in connection with a separate systematic review.

Blinding of participants and personnel (performance bias)
All outcomes
High risk

Quote: “This was a 12-center prospective randomised stratified parallel groups open factorial trial”.

Comment: trial confirmed as unblinded through personal communication with trial author.

Blinding of outcome assessment (detection bias)
All outcomes
High risk

Quote: “This was a 12-center prospective randomised stratified parallel groups open factorial trial”.

Comment: trial confirmed as unblinded through personal communication with trial author.

Incomplete outcome data (attrition bias)
All outcomes
Low risk

Quote: “Patients who withdrew from the bandage trial but continued to receive the randomised dressing continued to be followed up within the dressing trial. Patients continued to be assessed for healing following withdrawal from the trial in order to allow for a true “intention to treat” analysis.”

“A total of 159 patients were entered into the trial, of which three did not achieve pre randomisation selection criteria . . . these three were excluded . . . The remainder made up the trial population.”

Comment: ITT analysis undertaken.

Selective reporting (reporting bias)High riskComment: RCT protocol available, but no report of the HRQoL outcomes that were pre-specified in the protocol available.

Norkus 2005

Methods

Multicentred RCT (12 centres).

Country: 6 European countries.

Setting: not reported.

Sample size calculation: not reported.

Participants

97 patients.

Inclusion criteria: adult patients ≥18 years with highly exuding leg ulcers present for at least 4 weeks; ulcer size < 8 cm x 8 cm; ABPI ≥ 0.8.

Exclusion criteria: clinical signs of acute wound infection; severe eczema; lymphatic or malignant ulcers; systemic treatment with corticosteroids or other immunosuppressants.

 

Numbers randomised:

Group 1 (hydrocapillary): 49 participants;

Group 2 (polyurethane foam):48 participants.

 

Median participant age (range):

Group 1 (hydrocapillary): 70 (33-89);

Group 2 (polyurethane foam): 70 (29-97).

 

Number (%) male:

Group 1 (hydrocapillary): 21/70 (43);

Group 2 (polyurethane foam): 23/70 (48).

 

Unit of analysis: participant. 

Participant mobility: not reported.

 

Number (%) of participants with ulcer aetiology venous vs mixed arterial/venous vs arterial vs unknown (missing data):

Group 1 (hydrocapillary): 43/49 (88) vs 5/49 (10) vs 0/49 (0) vs 1/49 (2);

Group 2 (polyurethane foam): 43/48 (90) vs 2/48 (4) vs 1/48 (2) vs 2/48 (4).

 

Median (range) ABPI at baseline:

Group 1 (hydrocapillary): 1.0 (0.8-1.4), n = 47;

Group 2 (polyurethane foam): 1.0 (0.9-1.7), n = 47.

 

Baseline ulcer area cm2 - median (range):

Group 1 (hydrocapillary): 9.3 (0.9-38.1), n = 48;

Group 2 (polyurethane foam): 6.4 (0.5-51.4), n = 47.

 

Baseline ulcer duration years - median (range):

Group 1 (hydrocapillary): 1.0 (0.1-19.0), n = 48;

Group 2 (polyurethane foam): 0.7 (0.1-27.0 ), n = 47.

 

Ulcer infection:

People with clinical signs of acute wound infection were excluded from the trial.

 

Baseline quality of life – median WHO-5 Well-being Index scores:

Group 1 (hydrocapillary): 60;

Group 2 (polyurethane foam): 48.

 

Number (%) participants with medium exudate vs high exudate vs unknown (missing data):

Group 1 (hydrocapillary): 0/49 (0) vs 46/49 (94) vs 3/49 (6);

Group 2 (polyurethane foam): 1/48 (2) vs 46/48 (96) vs 1/48 (2).

Comment: there were missing data for some baseline variables.

Interventions

Group 1 : hydrocapillary (Alione,Coloplast);

Group 2: polyurethane foam (Tielle Plus and Tielle, Johnson & Johnson Medical).

Ulcers cleaned and debrided, if necessary, according to normal practice at the participating centre. Dressings changed when necessary (maximum of 7 days). In Group 2, Tielle Plus used at the start of the trial when wounds were highly exuding. Subsequently, Tielle used when dressing changes required < once/day. Ulcers and peri-ulcer skin assessed weekly for first 8 weeks after which assessment was fortnightly until the end of the trial.

 

Description of compression therapy: participants treated with compression therapy at the start of the study continued using it throughout the study. Compression therapy used in 36/49 (73%) of patients in Group 1 and 32/48 (67%) of patients in Group 2.

 

Length of treatment: leg ulcers treated until they healed, or for a maximum of 12 months. 

Length of follow up: 12 months.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: ulcers were traced using planimetry and photographed.

Proportion of ulcers healed: see above.

Change in ulcer size: not reported.

Healing rate: not reported.

Adverse events: research nurses evaluated odour, maceration, leakage, erythema and eczema on a 4-point scale: none, mild, moderate or severe.

Quality of life: quality of life assessed at start and end of the trial using the WHO-5 Well-being Index. Responses to 5 questions scaled from 0-5, then total multiplied by 4 to give a maximum value of 100. Higher scores equate to better well-being.

Cost: not reported.

Pain: participants reported wound pain between dressing changes, at assessment visits, or during dressing removal on a 4-point scale: none, mild, moderate or severe.

Dressing performance: reported exudate handling, but not dressing changes. Dressings were weighed to determine the amount of exudate. Dressing absorption measured on a 3-point scale: good, moderate or poor. Trial personnel asked to estimate additional wear time based on saturation of the dressing. Adherence of the dressing to the wound bed was also assessed.

Other outcomes assessed by the trial:

Participants evaluated their overall impression of the dressing and were asked to compare the trial dressing with their previous dressing (better, same, worse).

Comments: each participating centre was instructed in the use of the assessment scales prior to trial commencement.

Notes

Sponsor: Coloplast (trial number not reported).

 

Number (%) of participants withdrawing and reasons:

Group 1 (hydrocapillary): 21/49 (43) – 8 due to adverse events;

Group 2 (polyurethane foam): 25/48 (52) – 11 due to adverse events.

 

Number (%) of participants developing clinical signs of wound infection – all withdrew:

Group 1 (hydrocapillary): 5/49 (10);

Group 2 (polyurethane foam): 4/48 (8).

Trialists did not report whether these participants were included in the numbers withdrawing due to adverse events (above).

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

Quote: “The study used an open comparative block randomised multicentre design”.

Comment: sequence generation not reported.

Allocation concealment (selection bias)Unclear risk

Quote: “All were given a general medical examination to establish suitability for participation before being randomised to one of two treatment groups in an one-to-one ratio”.

Comment: allocation process not reported.

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskComment: no statement regarding blinding of participants or study personnel.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear risk

“Dressings were changed during . . . assessments . . . by the study nurses between . . . visits.”

Comment: outcome assessor blinding was not mentioned.

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskComment: numbers withdrawing reported by group, but only numbers withdrawing due to adverse events were detailed and reasons for other withdrawals were not stated. A higher proportion of participants withdrew from Group 1. The statistical analysis was carried out as ITT with last observation carried forward.
Selective reporting (reporting bias)Low risk

Comment: all trial outcomes described in the methods section of the report were included in the results section.

Unable to obtain RCT protocol.

Thomas 1997

Methods

RCT with 2 centres. Trial designed to compare 2 dressings in management of leg ulcers and pressure ulcers.

Country: Wales, UK.

Setting: community.

Sample size calculation: not reported.

Participants

Leg ulcer participants: 100 participants recruited from the community.

Inclusion criteria (leg ulcers): venous ulcers confirmed by medical history, clinical examination and ABPI > 0.8; wound maximum diameter 8 cm.

Exclusion criteria: < 16 years, known poor compliance with medical treatment; insulin-dependent diabetes; unlikely to survive study period; known adverse reaction to study dressings; or clinically infected wounds.

Numbers randomised:

Group 1 (hydrocolloid): 50 participants;

Group 2 (polyurethane foam): 50 participants.

 

Mean participant age (SD):

Group 1 (hydrocolloid): 75.3 years (14.4);

Group 2 (polyurethane foam): 73.4 years (13.2).

 

Number (%) male:

Group 1 (hydrocolloid): 16/50 (32);

Group 2 (polyurethane foam): 13/50 (26).

 

Unit of analysis: participant.

Participant mobility: not reported.

 

Baseline ulcer area mm2 - mean (range):

Group 1 (hydrocolloid): 335 (100-2758);

Group 2 (polyurethane foam): 431 (16-1876).

 

Baseline ulcer duration – number (%) participants with ulcers < 1 months' vs 1-3 months' vs > 3 months' duration:

Group 1 (hydrocolloid): 3/50 (6) vs 13/50 (26) vs 34/50 (68);

Group 2 (polyurethane foam): 2/50 (4) vs 9/50 (18) vs 39/50 (78).

 

Ulcer infection:

People with infected wounds were excluded.

 

Participant ulcer history: not reported.

 

Participant baseline exudate levels (all wound types):

Trialists reported no difference between groups in the degree of exudation, but no data presented.

 

Baseline pain (all wound types):

Trialists reported no difference between groups in terms of pain, but no data presented. It was not clear whether pain was specific to ulcer or more general.

Interventions

Group 1: hydrocolloid (Granuflex, ConvaTec);

Group 2: polyurethane foam (Tielle, Johnson & Johnson Medical).

Wounds cleansed using a sterile solution of NaCl 0.9%, as necessary. Dressings changed only when exudate leaked or seen to approach the edge of the dressing. All wounds formally assessed at weekly intervals.

 

Description of compression therapy: type 3C compression bandage (Tensopress) applied over orthopaedic wadding (Velband).

 

Length of treatment: 13 weeks. 

Length of follow up: 13 weeks.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: mentioned, but no estimates reported.

Proportion of ulcers healed: all wounds photographed and characterised according to proportion of epithelium, black (necrotic), yellow (sloughy) and red (granulation) tissue present. Planimetry used to determine the wound area from a tracing.

Change in ulcer size: not reported.

Healing rate: not reported.

Adverse events: details of adverse events documented.

Quality of life: not reported.

Cost: not reported.

Pain: pain or discomfort recorded by nurses at every dressing change.

Dressing performance: an estimate of exudate production and evidence of leakage recorded by nurses at every dressing change. Ease of dressing removal also recorded.

Other outcomes assessed by the trial: presence of odour.

Notes

Sponsor: sponsor not reported (trial number not reported).

Number of patients withdrawing and reasons:

Report contained no statement regarding withdrawals.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

Quote: “An open, randomised, controlled, two-centred, comparative study involving 199 patients was undertaken in the community”, and, “…patients…were allocated to the two treatment groups on a randomised basis, using a system of sealed envelopes.”

Comment: sequence generation not reported.

Allocation concealment (selection bias)Unclear risk

Quote: “…patients who complied with the inclusion criteria and gave informed consent in writing were allocated to the two treatment groups on a randomised basis, using a system of sealed envelopes”.

Comment: no statement that envelopes were opaque or sequentially-numbered.

Blinding of participants and personnel (performance bias)
All outcomes
Unclear risk

Quote: “An open, randomised, controlled, two-centered, comparative study involving 199 patients was undertaken in the community”

Comment: no statement regarding blinding of participants or study personnel.

Blinding of outcome assessment (detection bias)
All outcomes
Unclear risk

Quote: “An open, randomised, controlled, two-centred, comparative study involving 199 patients was undertaken in the community", and, “To ensure accurate data collection, all dressing changes were undertaken by dedicated research nurses”.

Comment: unclear whether nurses were blind to dressing allocation. 

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskComment: all participants randomised were accounted for in tabulated healing outcomes, but not all were accounted for in text reporting proportions of participants whose ulcers reduced in size (numbers missing: Group 1, 3/50 (6%); Group 2: 1/50 (1%)). The report contained no statement regarding withdrawals.
Selective reporting (reporting bias)Low risk

Comment: all trial outcomes described in the methods section of the report were included in the results section.

Unable to obtain RCT protocol.

Vanscheidt 2004

Methods

Multicentred RCT (15 centres).

Country: North America and Europe.

Setting: hospital outpatient clinics and community based.

Sample size calculation: 65 participants/group required for the trial to have 80% power to detect a 22% between-group difference in healing after 12 weeks of treatment, at the 0.05 significance level.  Required a total of 154 participants to obtain approximately 130 evaluable participants (from protocol supplied by trial sponsor).

Participants

107 people recruited from hospital outpatient clinics and the community.

Inclusion criteria: venous leg ulcer ≥ 2 cm2; clinically free of infection; ABPI ≥ 0.8. Diabetic people with a qualifying venous leg ulcer who were judged clinically to be under reasonable metabolic control (no history of hospitalisation to manage glucose levels within last 6 months) were able to participate.

Exclusion criteria: venous leg ulcers larger than 11 cm x 15 cm; people with ulcers secondary to arterial disease, vasculitis, neoplasms, or haematological disorders based on prior diagnoses; people with history of poor compliance with medical treatments; identified sensitivity to any of the dressings’ components; or an ankle circumference of < 18 cm.

 

Numbers randomised:

Group 1 (hydrocolloid): 55 participants;

Group 2 (hydrocellular foam): 52 participants.

 

Mean participant age (SD) [range]:

Group 1 (hydrocolloid): 62.8 years (15.5) [27.7-90.3];

Group 2 (hydrocellular foam): 68.4 years (14.4) [33.1-92.1].

 

Number (%) male:

Group 1 (hydrocolloid): 25/55 (45);

Group 2 (hydrocellular foam): 28/52 (54).

 

Unit of analysis: participant. 

Participant mobility: not reported.

 

Mean baseline ABPI (SD) [range]:

Group 1 (hydrocolloid): 1.04 (0.12) [0.80-1.36];

Group 2 (hydrocellular foam): 1.04 (0.15) [0.80-1.50].

 

Baseline ulcer area cm2 - mean (SD) [range]:

Group 1 (hydrocolloid): 11.7 (14.5) [1.1-76.2]

Group 2 (hydrocellular foam): 10.9 (11.1) [0.6-50.1]

 

Baseline ulcer duration years - mean (SD) [range]:

Group 1 (hydrocolloid): 3.3 (7.0) [0-40.0];

Group 2 (hydrocellular foam): 1.3 (2.3) [0-13.0].

 

Ulcer infection: ulcers had to be free of infection to be included.

 

Participant ulcer history: not reported.

 

Number (%) participants with no exudate vs minimal exudate (< 25% of dressing saturated) vs moderate exudate (25%-75% of dressing saturated) vs considerable exudate:

Group 1 (hydrocolloid): 0/55 (0) vs 20/55 (36) vs 28/55 (51) vs 7/55 (13);

Group 2 (hydrocellular foam): 4/52 (8) vs 20/52 (38) vs22/52 (42) vs 6/52 (11).

Interventions

Group 1: hydrocolloid (Versiva,ConvaTec);

Group 2: hydrocellular foam (Allevyn, Smith and Nephew).

Ulcers were sharp debrided, if necessary, according to local practice. Dressings changed as clinically indicated according to manufacturer recommendations with a maximum wear time of 7 days, more often if there was leakage or strike through. Topical agents applied for prophylaxis or for treatment of pre-existing conditions of the peri-wound area (e.g. eczema). Wound fillers could be used with foam dressing but not hydrocolloid dressing, and only if severe maceration observed following a wear time of < 2 days. Follow up occurred at least every 7 days, and more often if strike through occurred.

 

Description of compression therapy: high compression bandage (Surepress High Compression, ConvaTec) to ensure adequate sustained compression required for appropriate venous ulcer management.

 

Length of treatment: 12 weeks, or until healing of the ulcer, whichever came first. 

Length of follow up: 12 weeks or until healing of the ulcer, whichever came first.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: acetate tracings made at first visit, every 14 days thereafter, and at final visit. Ulcers photographed at first visit, after 6 weeks, and at final visit.

Proportion of ulcers healed: yes, defined as the rate of complete healing by the end of the trial.

Change in ulcer size: not reported.

Healing rate: measured as absolute (cm2) and percentage change/week.

Adverse events: reported numbers of patients with dressing-related and severe adverse events deemed unrelated to dressing, together with description of adverse events. Also, total number of adverse events/group reported for dressing-related adverse events. In addition, investigators assessed condition of peri-ulcer skin in relation to presence of maceration, erythema, eczema, lipodermatosclerosis, cellulitis, dermatitis and other conditions.

Quality of life: not reported.

Cost (resource use): dressing change frequency assessed by calculating wear time (days) and number of dressing changes/group.

Pain: evaluated at final evaluation using the Johns Hopkins Pain Rating Instrument (VAS: 1 = reduction in pain, 2 = increase in pain, 3 = no effect on pain, 4 = uncertain, 5 = unable to respond).

Dressing performance: overall investigator satisfaction with the dressing rated at final evaluation on a 5-point scale (1 = excellent, 2 = very good, 3 = good, 4 = fair, 5 = poor) for each study participant according to: exudate absorption (based on participant-reported dates and times of leakage), non-traumatic dressing removal, and ease of removal.

Other outcomes assessed by the trial:

Changes in ulcer bed (granulation tissue, epithelial tissue, fibrin, slough, eschar/necrotic tissue, other tissue).

Changes in surrounding skin.

Overall investigator satisfaction with dressing conformability, ability to soothe ulcer pain, protection of the surrounding skin, non-sensitizing properties, and ease of application.

Comment: the Johns Hopkins Pain Rating instrument is a generic VAS instrument that has not been validated for use in participants with wounds.

Notes

Sponsor: ConvaTec (trial number not reported).

Number of patients withdrawing and reasons:

The trialists reported that 31 (29%) of all participants withdrew before 9.6 weeks (participants had to complete at least 9.6 weeks of the assigned treatment to be included in analyses). Numbers of withdrawals by group and their reasons were not reported. No information about whether any participants withdrew after 9.6 weeks. 1 patient died in Group 1 (hydrocolloid), but unclear whether death was before or after 9.6 weeks.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

Quote: “Patients were randomly assigned to receive a protocol of care which included one of two foam primary dressings covered with a compression bandage”, and, “The randomisation schedule will be generated by the statistician” (from protocol).

Comment: sequence generation not reported.

Allocation concealment (selection bias)Unclear risk

Quote: “Patients were randomly assigned to receive a protocol of care which included one of two foam primary dressings covered with a compression bandage”.

Comment: allocation process not reported.

Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskComment: no statement regarding blinding of participants or study personnel.
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskComment: no statement regarding blinded outcome assessment.
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk

Quote: “All data were analysed on an intent-to-treat basis, including all patients enrolled in the study, unless specified in the text as 'evaluable' patients as defined by completing at least 9.6 weeks of the assigned dressing protocol”.

Comment: trialists reported that 31 (29%) of all participants withdrew before 9.6 weeks, but did not state if any further participants withdrew after that point. Numbers withdrawing by group and reasons for withdrawal were not reported. Choice of 9.6 weeks as a threshold for including participants in analyses not explained.

Selective reporting (reporting bias)High riskComment: a number of evident mismatches between the published report and the RCT protocol (supplied by the trial sponsor). Trial report mentioned use of scales to assess outcomes such as leakage and ease of dressing removal, but these were not mentioned in the protocol. The pre-specified outcome of patient-reported leakage (from a patient diary) was not reported. Cost of managing complications was specified in the protocol, but was not in the trial report.

Weiss 1996

Methods

RCT, pilot study.

Country: North America.

Setting: clinic.

Sample size calculation: not reported. Trialists reported that statistical analysis was not performed because the total number of participants enrolled needed to be higher.

Participants

18 patients with venous leg ulcers.
Inclusion criteria: ulcer present for at least 2 months and between 1-4 cm2 in size; venous origin of ulcers confirmed by digital photoplethysmography with refill times of < 25 seconds.

Exclusion criteria: people with an ABPI < 0.8.

 

Numbers randomised:

Group 1 (polyurethane foam): 10 participants;

Group 2 (hydrocellular foam): 8 participants.

 

Participant age: not reported.

Number (%) male: not reported. 

Unit of analysis: patients appeared to be the unit of randomisation and analysis. Trialists reported that 20% of patients had multiple ulcers, but did not report how this was handled in terms of treatment allocation and analysis. 

Participant mobility: not reported. 

Baseline ulcer area: average 2 cm2 for all patients; data/group not provided. 

Baseline ulcer duration: not reported. 

Ulcer infection: not reported. 

Patient ulcer history: approximately 20% of patients had recurrent ulcers, but data/group not provided. 

Participant baseline exudate levels: not reported. 

Comments: minimal baseline data provided.

Interventions

Group 1: polyurethane foam (Cutinova, Beiersdorf now BSN Medical);

Group 2: hydrocellular foam (Allevyn, Smith and Nephew).

Dressings changed every 24-72 h, depending on volume of exudate. Antibiotics not routinely administered except when a secondary superficial infection was noted at an assessment visit.

 

Description of compression therapy: all patients received compression stockings (Jobst UlcerCare) consisting of an inner graduated compression stocking providing 10 mmHg to be worn 24 h/day, plus daytime use of a zippered graduated compression stocking of 30 mmHg (total additive compression 40 mmHg).

 

Length of treatment: 16 weeks. 

Length of follow up: 16 weeks.

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: evaluated using weekly acetate tracings to determine square area of remaining ulcer tissue. Photographic documentation also performed weekly.

Proportion of ulcers healed: reported as time to healing.

Change in ulcer size: not reported.

Healing rate: not reported.

Adverse events: incidence of allergic reaction reported.

Quality of life: not reported.

Cost: not reported.

Pain: participant evaluation of ulcer pain (assessment method not reported).

Dressing performance: not reported.

Other outcomes assessed by the trial:

Compliance.

Dressing comfort.

Notes

Sponsor: trial sponsor not reported (trial number not reported).

 

Number (%) participants withdrawing and reasons:

Group 1 (polyurethane foam): 0/10 (0);

Group 2 (hydrocellular foam): 3/8 (38): allergic reaction = 1; patient choice = 1; moved away = 1.

 

Trial undertaken as a pilot study.  Unable to identify whether full trial was ever undertaken (unable to locate trial author or protocol).

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

Quote: “Patients with venous ulcers with an average of 2 cm2 were randomly assigned . . .”.

Comment: sequence generation not reported.

Allocation concealment (selection bias)Unclear risk

Quote: “Patients with venous ulcers with an average of 2 cm2 were randomly assigned . . .”.

Comment: allocation process not reported.

Blinding of participants and personnel (performance bias)
All outcomes
High risk

Quote: “The study was a randomised, non-blinded evaluation . . .”.

Comment: stated as unblinded.

Blinding of outcome assessment (detection bias)
All outcomes
High risk

Quote: “The study was a randomised, non-blinded evaluation . . .”.

Comment: stated as unblinded.

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskComment: number of participants withdrawing and reasons were reported; none withdrew from Group 1 and 3 withdrew from Group 2. Trial report suggested that all participants included in final analysis of healing, but unclear whether pain and other outcomes included all participants.
Selective reporting (reporting bias)Low risk

Comment: all trial outcomes described in the methods section of the report were included in the results section.

Unable to obtain RCT protocol.

Zuccarelli 1992

  1. a

    Abbreviations

    < = less than
    > = more/greater than
    ≥ = more/greater than or equal to
    ABPI = ankle-brachial pressure index
    h = hour(s)
    HRQoL = health-related quality of life
    ITT = intention-to-treat analysis
    NaCl = sodium chloride (common salt)
    RCT = randomised controlled trial
    TcPO2 = transcutaneous oxygen pressure
    VAS = visual analogue scale
    VRS = verbal rating scale

Methods

Single-centred RCT.

Country: France.

Setting: leg ulcer clinic.

Sample size calculation: not reported.

Participants

38 outpatients recruited from a leg ulcer clinic.

Inclusion criteria: people >18 years; 1 or more leg ulcers of at least 4 weeks duration; venous insufficiency (confirmed by Doppler exam) in the leg with the ulcer; and ABPI ≥ 0.8.

Exclusion criteria: pregnant women (or those who might be pregnant); a history of myocardial infarction in previous 6 months; unstable angina; non-controlled arterial hypertension; rheumatoid arthritis; or unstable diabetes; secondary infected or necrotic ulcers.

 

Numbers randomised:

Group 1 (hydrocolloid): 19 participants;

Group 2 (hydrocellular foam): 19 participants.

 

Mean participant age (SD):

Group 1 (hydrocolloid): 77.3 years;

Group 2 (hydrocellular foam): 70.1 years.

 

Number (%) male:

Group 1 (hydrocolloid): 2/19 (11);

Group 2 (hydrocellular foam): 6/19 (32).

 

Unit of analysis: participant. Where there were multiple ulcers, the largest was used as the reference ulcer.

 

Participant mobility: ambulatory patients recruited.

 

Mean baseline ulcer area cm2:

Group 1 (hydrocolloid): 6.9;

Group 2 (hydrocellular foam): 9.8.

 

Mean baseline ulcer duration weeks:

Group 1 (hydrocolloid): 37.4;

Group 2 (hydrocellular foam): 48.9.

 

Ulcer infection: secondary infected or necrotic ulcers excluded.

 

Number (%) participants with previous ulcer history:

Group 1: (hydrocolloid dressing) 17/19 (89);

Group 2: (hydrocellular foam dressing) 14/19 (74).

Raw numbers extrapolated by review authors from other information given.

 

Number (%) participants with previous history of surgery vs sclerotherapy vs DVT:

Group 1 (hydrocolloid): 3/19 (16) vs 11/19 (58) vs 6/19 (32);

Group 2 (hydrocellular foam): 7/19 (37) vs 11/19 (58) vs 6/19 (32).

 

Mean pain scores (derived from numeric scale with range 0-2.7):

Group 1 (hydrocolloid dressing): 2.3;

Group 2 (hydrocellular foam dressing): 2.6.

Values read from figure.

Interventions

Group 1: hydrocolloid (Duoderm, ConvaTec);

Group 2: hydrocellular foam (Allevyn, Smith and Nephew).

Dressings changed every week, or more often when discomfort, irritation, leakage of exudate, or un-sticking of the dressing. Application of local corticosteroids on peri-ulcer skin authorised in case of varicose eczema. Ulcer assessed at 0, 4, 8 and 12 weeks.

 

Description of compression therapy: a 2-layer, standard elastic bandage system: first layer (Nylex) kept in place, whereas second layer (Biflex) removed by participant before going to bed and re-applied before getting up in the morning.

 

Length of treatment: 12 weeks, or until the ulcer healed, whichever was sooner. 

Follow up: 12 weeks, or until the ulcer healed, whichever was sooner. 

Outcomes

Reporting of outcomes relevant to this review:

Time to healing: not reported.

Proportion of ulcers healed: investigator traced ulcer contours and took photographs.

Change in ulcer size: not reported.

Healing rate: not reported.

Adverse events: evaluated, but assessment method not reported.

Quality of life: not reported.

Cost: recorded number of dressing changes.

Pain: method of data collection not reported; numerical scale used to present data using a range between 1.3-2.7, full range of scores not stated; lower scores represented less pain; data presented graphically.

Dressing performance: not reported.

Other outcomes assessed by the trial: no other outcomes assessed.

Notes

Sponsor: Smith & Nephew (trial number not reported).

Number of patients withdrawing and reasons for withdrawal: trial report contained no statement regarding withdrawal of participants.

Article translated from French.

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear risk

Quote: “Thirty eight patients were recruited and randomised to receive either Allevyn or the hydrocolloid”.

Comment: sequence generation not reported.

Allocation concealment (selection bias)Unclear risk

Quote: “Thirty eight patients were recruited and randomised to receive either Allevyn or the hydrocolloid”.

Comment: allocation process not reported.

Blinding of participants and personnel (performance bias)
All outcomes
Unclear risk

Quote: “An open, single-centre clinical trial”.

Comment: no statement regarding blinding of participants or study personnel.

Blinding of outcome assessment (detection bias)
All outcomes
Unclear risk

Quote: “The investigator traced the contours of the ulcer and took photographs”.

Comment: no statement regarding blinded outcome assessment.

Incomplete outcome data (attrition bias)
All outcomes
Low riskComment: the report contains no statement regarding withdrawals, although it appears that all participants are included in the tabulated healing outcome data.
Selective reporting (reporting bias)Low risk

Comment: all trial outcomes described in the methods section of the report were included in the results section.

Unable to obtain RCT protocol.

Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion
  1. a

    Abbreviation

    VLU = venous leg ulcer(s)

Anonoymous 1997Not an RCT (review article translated from German).
Bale 1998Report did not present results by ulcer type (< 75% in each treatment arm were VLUs). Attempts to obtain data for only participants with VLUs from trial sponsor unsuccessful (email communication).
Banks 1997Report did not present results by ulcer type (< 75% in each treatment arm were VLUs). Attempts to obtain data for only participants with VLUs from trial sponsor unsuccessful (email communication).
Berard 1986Not an RCT (single-arm trial of hydrocolloid dressing in pressure ulcers. Article translated from Spanish).
Bressieux 2007Not an RCT (report of 2 single-arm trials evaluating foam dressings).
Brown-Etris 2004Abstract with limited information.  Attempts to obtain full report from trial author unsuccessful (email communication).
Capillas Pérez 2000Not a treatment of interest (RCT comparing hydrocolloids, hydrogels and alginate dressings in people with venous leg ulcers. Article translated from Spanish).
Cherry 1984Not an RCT (single-arm trial of hydrocolloid dressing in venous leg ulcers).
Colgan 1996Foam dressing not the only systematic difference across treatment groups (bandaging systems were different in each group).
Collier 1992Did not report the proportion of participants with leg ulcers of venous origin. Information no longer available from trial author or sponsor (email communication).
Dmochowska 1999Foam dressing not the only systematic difference across treatment groups (alginate group only received secondary absorbant dressing).
Kurring 1994Not an RCT (single-arm trial of a foam dressing in leg ulcers of unstated aetiology).
Larsen 2005Not an RCT (non-randomised trial of two foam dressings).
Meaume 2012Not an eligible comparison. Both dressings are foam, one plain and the other impregnated with Nano-OligoSaccharide Factor (NOSF). The trial therefore evaluates the effects of applying the NOSF, and not the effect of the foam dressing.
Moffatt 1992Not a treatment of interest (RCT comparing hydrocolloid with a knitted viscose dressing in venous leg ulcers).
Moody 1991Not an RCT (single-arm trial of alginate dressings in pressure ulcers and non-healing burns).
Mulder 1995Abstract with limited information.  Full trial report no longer available (email communication with trial author).
Pessenhofer 1992Foam dressing not the only systematic difference across treatment arms (sterile gauze group only received Fibrolan for coated wounds. Confirmed from both the English language primary reference and secondary reference translated from German).
Pottle 1987Not an RCT (case series of hydrocolloid for leg ulcers of unstated aetiology).
Price 2004Not treatment of interest (RCT evaluating a silver-impregnated foam dressing in venous leg ulcers).
Reynolds 2004Foam dressing not the only systematic difference across treatment arms (the foam group could also receive an alginate or a hydrocolloid dressing as part of the standard dressing protocol of the treatment centre).
Romanelli 1999Less than 75% of participants had leg ulcers of venous origin. Information not available from trial author for only the participants with venous leg  ulcers (email communication with trial author).
Rubin 1990Foam dressing not the only systematic difference across treatment arms (bandaging systems were different in each group).
Schulze 2001Foam dressing not the only systematic difference across treatment arms (alginate group only received secondary film dressing that was changed to a sterile swab dressing for 50% of the group half-way  through the trial).
Scurr 1993Not treatment of interest (foam dressing is secondary dressing over an alginate dressing compared with alginate dressing with a film dressing as secondary dressing).
Sironi 2003Not treatment of interest (RCT comparing treatment "systems" comprising different dressings and topical applications in venous leg ulcers where the dressing would not be the only systematic difference).
van Rijswijk 1985Not an RCT (single-arm trial of hydrocolloid dressing in leg ulcers of unstated aetiology).
Verdu Soriano 2006Not an RCT (observational study of the use of foam dressings in venous leg ulcers).
Winter 1996Not a treatment of interest (RCT comparing hydrocolloid with a gauze dressing in venous leg ulcers).
Wollina 1997Not an RCT (single-arm trial of foam dressing in participants with leg ulcers, pressure ulcers and other wounds).

Characteristics of studies awaiting assessment [ordered by study ID]

Jørgensen 2008

MethodsRandomised controlled open trial.
Participants40 patients with leg ulcers of venous or mixed venous and arterial aetiology.
InterventionsPolyurethance foam dressing (old Biatian non-adhesive) compared with a polyurethane foam dressing (new Biatian non-adhesive).
OutcomesChange in ulcer size.
NotesReported as an abstract with limited information. Trying to obtain full report from trialists.

Romanelli 2008

MethodsSingle-blinded randomised controlled trial.
ParticipantsPatients with venous leg ulcers.
InterventionsPolyurethance foam dressing (Suprasorb P) compared with a bio-cellulose wound dressing (Suprasorb X).
OutcomesChange in ulcer size, pain.
NotesReported as an abstract presenting interim results for 19 patients. Final results report submitted to peer-review journal by trialists (email communication). Full report not available from trialists at present (email communication). To be reassessed at update for availability of peer-review publication.

Characteristics of ongoing studies [ordered by study ID]

Badiavas 2011

Trial name or titleA post marketing study of Apligraf in non-healing wounds of subjects with venous leg ulcers.
MethodsSingle-centred, randomised controlled trial.
ParticipantsPatients with a clinically non-infected full-thickness venous leg ulcer. Target number of participants = 30.
Interventions

Group A: bio-active cell based dressing (Apilgraf);

Group B: standard dressing regimen - foam dressing (e.g. Mepilex) and 4-layered compression system (e.g. Profore).

OutcomesComplete healing at 24 weeks.
Starting dateMarch 2011 - still recruiting.
Contact information Bayer 2009 Study Director.
NotesTrial number NCT01327937. Trial sponsor: Organiogenisis. Principal Investigator, Evangelos Badiavas 2011, contacted to request report once trial completed (email: ebadiavas@med.miami.edu).

Bayer 2009

Trial name or titleSilica gel fiber wound dressing for chronic venous leg ulcers.
MethodsMulticentred, randomised controlled trial.
ParticipantsPatients with chronic venous leg ulcers. Target number of participants = 126.
Interventions

Group A: silica gel fibre dressing;

Group B: standard care with dressing changes twice/week using Mepitel and Mepilex wound dressings.

OutcomesTime to healing, complete healing and change in ulcer size at 12 weeks.
Starting dateApril 2009. Terminated 16 July 2012.
Contact information Bayer 2009 Study Director.
NotesTrial number NCT00998673. Trial sponsor (Bayer 2009) contacted via email to request any available results to termination.

Vas 2008

Trial name or titleEffectiveness of acupuncture, special dressings and simple, low-adherence dressings for healing venous leg ulcers in primary healthcare.
MethodsMulticentred, cluster-randomised controlled trial.
ParticipantsPatients with venous leg ulcers. Target number of participants = 375.
Interventions

Group A: compression therapy + low-adherence dressings + acupuncture;

Group B: compression therapy + special dressings (hydropolymer dressings);

Group C: compression therapy + low-adherence dressings.

OutcomesComplete healing at 3 months, change in ulcer size, pain, quality of life.
Starting dateApril 2008. Completed.
Contact informationDr Jorge Vas 2008 (jorgef.vas.sspa@untadeandalucia.es).
NotesTrial number ISRCTN26438275. No results available yet, as still in analysis phase (email communication with principal investigator).

Ancillary